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Chapter 2: Killing or injuring creatures on Shabbos
1. The Primary Melacha that was in the Tabernacle-Slaughtering:
2. The Biblical Prohibitions included in the above principal Melacha:
A. Killing in forms other than slaughtering:
Not only is slaughtering [included in this principal prohibition] but [also] anyone who takes the soul from any species of animal, bird, fish, and rodent, whether [he did so] by slaughtering it [and] whether by tearing it [open, and] whether by hitting it, he is liable.
Strangling: One who strangles a creature until it dies is [transgressing] an offshoot of [the prohibited action of] slaughtering. [As will be explained in Halacha 5 regarding removing fish from water to the point that it can no longer live.]
B. Injuring a creature:
- Causing a creature to bleed:
The taking of life [prohibition] which one is liable for, is not only when one removes the entire life-force from the creature [i.e. kills it], rather even if one removed [only] a part of its life-force he is liable. For example, one who [injures an animal to the point that he] takes out blood from one of the limbs of the creature then he is liable for taking out life from that area being that blood contains [ones life-force which is] the soul.
Scratching a pimple/boil on Shabbos: It is forbidden to scratch a boil [on Shabbos] as doing so removes blood and contains the prohibition of inflicting a wound.
- Causing a bruise to a creature:
[Furthermore, he is] not only [held liable] if blood actually comes out [of its skin], but even if one bruised one of the creatures limbs to the point that blood [vessels have been broken and] gathered under the skin [thus causing a “black and blue mark”] then even though [the blood] has not gone out [of the skin] he is liable being that it is a bruise which will never be replaced. As once the blood [vessels have been broken and] gathered under the skin it can never return back to its place, and its only that the skin is preventing it from going out, and he is thus liable for taking out the blood of that area.
Bruising an animal and the like: [However] the above only applies to a bruise made in a person or domestic and wild animal or bird or in [any of] the eight rodents mentioned in the Torah (in Parshas Shemini) which are the weasel, the mouse [the toad, the porcupine or hedgehog, the lizard, the snail, and the mole] of which each one of these has skin which prevents the blood from going out.
Bruising an insect: However, one who bruises other creeping creatures and insects is not liable until he removes blood from them. However, if the blood gathered [in its body] and did not leave, then this is a [type of] bruise which will [have the blood] return back to its place, as if the blood had left its area then it would have come out being that it has no skin preventing it.
Disciplining children on Shabbos:
It is permitted to discipline or punish children on Shabbos. One may thus lock a child in his room for disciplinary purposes. Nonetheless, it is possibly even Biblically forbidden to hit or spank a child if doing so can cause a bruise to the child. Furthermore, it is not in the spirit of Shabbos to show anger or fury, or give punishment even for the sake of Chinuch, as learned from the reason why the Torah prohibited a Beis Din from giving punishment on Shabbos. The Torah desired that Shabbos be a day of rest for all, even those who deserve punishment, and hence one is to abstain from punishing or showing any anger on Shabbos to the utmost extreme.
C. Killing or injuring not for a use of the creature itself:
Killing for self-use: It was already explained in chapter 278 [Halacha 1-2] that there are opinions who say that a Biblical [Shabbos] prohibition only applies if the [forbidden] action was done for its own need, meaning that one needs the actual item to which the action was done to.
What is considered a self-use? Therefore one who removes the life [of a creature] is only liable if he has a need for the body of the creature which had its life-force removed from, or [if he needs] its skin, or he needs the soul which he took out from it, meaning the blood that has left it in order to give it to his dog, or if he bruises a person which is his enemy and he thus desires for blood to come out from him so that he witness revenge on his foes (see Choshen Mishpat chapter 424 [Halacha 2]). [Likewise one is liable if he makes a bruise in an animal for the sake of weakening it in order to capture it, or because one is angry at his friend and hence injures his animal.] However, one who kills a snake in order to prevent it from injuring him then this is an action done which is not self-needed being that he does not need either the body of the snake or its blood and he is only killing it in order to be saved from injury.
Releasing blood for medical purposes: One who has a tooth ache which causes him such pain that his entire body feels sick (is allowed to transgress Shabbos through a gentile) [and] may tell the gentile to remove [the tooth]. (And according to those opinions which say that any action which is not done for its own use is only Rabbinically forbidden then it is permitted to remove [the tooth] through a gentile even if the entire person’s body has not become sick [so long as it is more than a mere ache] as was explained [in Halacha 328/20])
D. The killing of creatures which do not reproduce-Fleas and Lice:
One is only liable for removing life-force on species of creatures which reproduce and are created through [the union of] a male and female, [as will be explained below in Halacha 4] Nevertheless [killing] the flea contains the [Biblical prohibition] of taking a life even though it is created from earth and does not reproduce, because all [creatures] that are created from earth have vitality as if they were created from male and female, as initially all creatures were created from earth as it says [in the Torah] “And G-d said let the earth extract….etc.”.
Summary of the Biblical prohibition of killing a creature:
It is a Biblical prohibition to kill or remove blood from any creature. Included in this is strangling a creature, such as taking a fish out of the water to the point that it can no longer live.
However, it is only Biblically prohibited to do the above if:
1. The creature was killed or bruised in order to use its body for a certain purpose, such as to eat or for its skin and the like. [or if one casually killed it and it is a type of creature which is generally killed for the above purpose].
2. The creature reproduces and is thus not a spontaneous generation, with exception to if it is created from earth in which case it too is included in the Biblical prohibition.
May one cause a bruise [black and blue mark] to a creature?
Any creature which has skin, which includes all animals, and birds, one is Biblically liable for forming a bruise on them. However, by creeping creatures and insects which do not have skin one is not liable until blood actually leaves their body.
Matters that are forbidden to be done due to the causing an injury prohibition:
Question: [Thursday, 23rd Sivan 5781]
I live in Brazil where the Covid crisis is rampant, deadly, and unbearable on the healthcare system and was lucky enough to have a Covid vaccine secured on my behalf. There are not enough vaccines and not everyone is eligible to receive it. The problem is that the date that they chose to administer the vaccine to me is on Shabbos. It is very difficult to reschedule and there is no guarantee that I will be able to get a vaccine at a later date. May I get the vaccine on Shabbos? If yes, what should I do about carrying my identification card to the hospital as they will not administer the vaccine if I cannot prove identification?
You may receive the vaccine on Shabbos in such a case, and you should arrange with a Gentile to carry your identification card for you to the hospital.
Explanation: Covid-19 is considered a potentially lethal illness and is thus under the category of danger of life for which one can desecrate Shabbos in order to help save. This certainly applies in a country that the illness is rampant and spreading like wildfire and whose medical establishment is overwhelmed with cases to the point that they simply cannot provide oxygen for all those who need it, hence exacerbating the death toll. The vaccine is medically considered to be effective to prevent the illness, and hence it is permitted and even an obligation to take it on Shabbos if it is not available to be taken another time, or there is serious doubt as to whether the opportunity will arise later. In truth, even if the Covid disease were not to be lethal but simply cause one to become bedridden with illness, as occurs in most cases, it would be permitted for one to take the vaccine on Shabbos in such a case, being that it is administered by a Gentile, and it is permitted for one to perform even biblical Melacha through a gentile on Shabbos for one who is bedridden, or to prevent an illness that can cause one to become bedridden. For this reason, one may likewise ask a gentile to carry his identification card. This especially applies in this case that in truth the Melachos involved in giving a vaccine may not be biblical at all.
Sources: See regarding the allowance of taking vaccines on Shabbos if they cannot be taken another day: SSH”K 32:62; Rav SZ”A in Shulchan Shlomo Erchei Refua p. 60-61; Piskeiy Teshuvos 328:53; See regarding desecrating Shabbos through a gentile for one who is ill: Admur 328:19; See regarding desecrating Shabbos to prevent an illness: Rav SZ”A in Shulchan Shlomo Erchei Refua p. 61; SSH”K 34:16; Piskeiy Teshuvos 328:2; See regarding if a vaccine even involves a Biblical prohibition: Admur 328:32; Tzitz Eliezer 8:15; 9:17; 10:25; 13:45; 14:9; Shevet Halevi 1:61; 8:79; 9:75; Divrei Yisrael 1:103; Nachalas Meir 15; Or Letziyon 2:26-20; Yabia Omer 9:108SSH”K 32:58; Piskeiy Teshuvos 328:53
3. The Rabbinical prohibition
Rabbinically forbidden to kill even not for a self-use: Any [forbidden] action which is not done for self-use is despite not being liable on, is Rabbinically forbidden [with exception to when done to prevent danger as will be explained].
Summary-The Rabbinical prohibition:
It is Rabbinically prohibited to kill or injure a creature when done not in order to use its body or blood.
4. The killing of creatures which do not reproduce-Fleas and Lice:
One is only liable for removing life-force on species of creatures which reproduce and are created through [the union of] a male and female, however insects which are created from [the bacteria found in] feces and from spoiled fruits and the like, such as for example worms [that grow] in flesh and like [the] worms which are found in legumes, then one who kills them exempt [from liability].
The reason for this is: because in the Tabernacle the taking of a life was only done to rams, techashim and chilazon which are [creatures] that reproduce and are born from a [union of] male and female.
Killing creatures which are created from earth: Nevertheless [killing] the flea contains the [Biblical prohibition] of taking a life even though it is created from earth and does not reproduce, because all [creatures] that are created from earth have vitality as if they were created from male and female, as initially all creatures were created from earth as it says [in the Torah] “And G-d said let the earth extract….etc.”.
Killing lice: What is considered a flea? This is a black insect which jumps. However, the white insect that crawls is called lice and is permitted to kill it on Shabbos being that it is [created] from sweat.
Killing lice when checking one’s clothing for them: However this [allowance] only refers to when one happens to find a lice on his flesh or [happens to] find it on his clothes. However, one who is [in the process of] cleaning his clothing of lice then he may [only] squeeze them with his fingers [without killing them] and throw them (even into water). However, it is forbidden to kill it with his hands as since he is cleaning his clothing of lice, we suspect that he may come to also find fleas and also kill them.
Killing lice when checking one’s hair for them: However, when checking one’s head [for lice] it is permitted for him to kill the lice with his hands being that fleas are not commonly found on one’s head.
Removing lice from skins: One may not remove lice form the skins of fox and the like being that [in the process] one removes hair from the skin which contains the sheering prohibition, and although it is done unintentionally, nevertheless it is an inevitable occurrence [and is thus forbidden].
The general rule: It is only Biblically forbidden to kill creatures which were born from a male and female union, or which were spontaneously created from earth such as fleas. However, killing a spontaneous creation not created from earth does not contain a Biblical prohibition [However regarding if doing so contains a Rabbinical prohibition, see Q&A.]
May one kill lice? Yes, as lice reproduce through sweat and not through male and female union. [See Q&A 3]
May one check someone’s hair for lice on Shabbos? Yes, and one may also kill them in the process. [However, he may not do so using a lice comb being that it pulls out hair in the process.]
May one check clothing for lice on Shabbos? Yes, although he may not kill them with his hands upon doing so. As well, it is Biblically forbidden to remove lice from animal skins.
May one kill fleas? No, as they are created from earth which has the equivalent life-force to having been created through a male and female.
May one kill worms that grow in meat and inside legumes? One is not Biblically liable for doing so [although it is Rabbinically forbidden to do so according to some opinions as will be explained below in the Q&A.]
May one kill insects that are born from waste but have ability to reproduce through male and female?
It is disputed amongst Rishonim whether it is possible for creatures that were not created from male and female have ability to reproduce. Practically, such insects are included within the Biblical prohibition.
May one today kill lice even though we see with our own eyes that it lays eggs?
The vast majority of Halachic authorities, including the Lubavitcher Rebbe, rule that the laws of the Torah are not negotiable, and thus once the ruling has been given that lice are permitted be killed being that they are born from sweat, this is the final ruling both for leniency and stringency irrelevant to what scientists and biologists may say. However, there are opinions which say that in light of the scientific and biological discovery that lice reproduce, it is proper to be stringent and not kill the lice today. [See note]
May one kill insects that were created from rotting fruits and meat?
Although doing so does not contain a Biblical prohibition as stated above, there is discussion as to whether it contains a Rabbinical prohibition. Some Poskim rule that doing so is permitted, just like lice. Others rule that it is Rabbinically forbidden, and so is implied from Admur.
May one kill insects that have grown within fruits prior to them having spoiled?
If they grew on the fruits while attached to the tree then it is forbidden to kill them. Others go on to further say that even if they grew when detached, but prior to spoilage of the fruit, they are forbidden to be killed. It is possible to learn this way in Admur as well.
5. Removing a fish from water:
One who strangles a creature until it dies is [transgressing] an offshoot of [the prohibited action of] slaughtering. Therefore, if one took a fish out of a bucket of water, and left it [outside the water] until it died then he is liable for strangulation. [To be liable], one does not have to [leave it out] until it completely dies but rather as soon as it [is left out to the point that] the width of a “Sela” of it has become dry between its fins, then one is liable even if he returns afterwards back into the water, as [once it has been left out for this long] it is no longer able to live. [Furthermore, to be liable one does] not [have to leave it out] until it actually dries but rather even if [it has been left out to the point that] when one touches it with a finger mucus comes out from it and gets pulled out with the finger [he is liable].
Asking a gentile to remove a fish from water: Therefore, one must be careful to not tell a gentile to take out a fish from a barrel of water even if he fears that it will die there [in the water, and thus contaminate the water and cause him a loss].
Removing a fish from a river or pool of water: All the above is referring to when he took out the fish from an area that it was already trapped in and was not lacking any further trapping at all, such as for example [the fish was in a] bucket or barrel (see chapter 497 [Halacha 1]). However, if one took it out from an area where it was lacking further trapping, such as for example [taking a fish out from] a river or pool, then even if he immediately returned it into water that is in a vessel, [nevertheless] he is liable for trapping. [Furthermore] even if one did not catch it with his hand at all, but rather simply draw it out of the river with a bucket of water, then he is liable for trapping as when [the fish] is inside a bucket it does not lack any further trapping.
It is a Biblical prohibition to strange a creature, such as taking a fish out of the water to the point that it can no longer live.
May one ask a gentile to remove a fish for him from a bucket of water?
May one remove a fish from a bucket of water and then replace it right away into other waters prior to its drying?
No, due to Muktzah. However, one may ask a gentile to do so [or remove it with a Shinui].
6. Killing dangerous animals and creatures:
A. Creatures that definitely have a deadly bite or sting:
Any wild animal and crawling creature which bites and definitively kills, such as a lethally venomous snakes and a rabid dog and the like of other dangerous creatures which have a definite deadly bite, then it is allowed to kill them on Shabbos even if they are not chasing after one at all [and even if they are running away from him]. [One may even search for the creature to kill it if it is found in an area that people are commonly found in.]
The reason for this is: because there is danger of life involved [in refraining from] killing them as they may [come to] kill a Jew, and [the rule is that whenever there is] any possibility [that a] life [will be endangered] then it pushes off Shabbos, [and allows one to do] even a complete Biblically [forbidden] action even according to those opinions which say that even an action which is not done for its own use one is Biblically liable on.
B. Creatures which are not deadly but cause bodily injury [in contrast to mere pain]:
- First Opinion:
If the creature is chasing oneself: Other dangerous creatures, even those which definitily do not kill with their bite but rather only damage the body, such as snakes and scorpions in areas that they never kill with their bite [or sting] and rather only damage, and so too any creature of the like, then there are opinions who say that if [these creatures] are chasing him then it is permitted to kill them according to those who say that any action which done not for its own use is only Rabbinically forbidden. [Regarding insects and the like which only cause mere pain-see next Halacha 7-9!]
Their reasoning is: because in a situation that involves bodily injury the [Sages] did not decree [against doing a Rabbinically forbidden action, which includes any action that is not done for its own use]. This case is not similar to the [case of the] flea which is in the midst of stinging ones flesh in which case it is forbidden to kill it, [as] the flea does not cause injury to the body but rather pain alone.
If these creatures are not chasing oneself: However, if [these creatures] are not currently chasing after him and it is only that one is worried [that they may do so] in the future, then it is forbidden to kill them in a way that it is blatantly obvious that it was intentionally done. However, it is permitted to trample on it while in the midst of casually walking even if he has intention in doing so in order to kill it, as long as he makes it appear as if he is casually walking and does not intend at all to kill it.
The reason for this is: because since an action which is not done for its own use is only Rabbinically forbidden [therefore it is not forbidden in this case as] the [Sages] did not decree at all against [doing an action even when not for its own use] in a case that involves bodily damage even if there is only mere doubt [as to whether bodily damage will occur]. However, in this case [that they are not chasing him] one needs to alter his method of killing them as much as it is possible for him change, which means that he is to make himself appear as if he does not intend to kill them.
- Other Opinions:
[However] according to those opinions which say that even an action which is not done for its own use one is [Biblically] liable on, it was only permitted to kill creatures which are chasing after him and to trample on [creatures] casually when they are not chasing after him, by those species of animals and crawling creatures which have the possibility of having a deadly bite. However, a creature which never kills with its bite is forbidden to even [casually] trample on it, and even if it is running after oneself, being that one may not desecrate Shabbos with a complete Biblically [forbidden] action in order [to prevent only] bodily damage.
- The Final Ruling:
The main Halachic opinion is like the former opinion, however nevertheless every meticulous person should be strict upon himself, regarding this [possible] Biblical prohibition, in a situation that it is possible [for him to refrain from killing it]. Such as if it is not running after him then he should not trample it if it is possible for him to guard himself from it and to warn others to beware of it.
C. Killing creatures which at times can be deadly and at times not that are not chasing after him:
Even by those species of animals and crawling creatures which carry a doubt regarding the deadliness of their bite, as at times they can kill and at times they will not kill, one must alter his method of killing them so long as they are not chasing after him. [Thus, one may only kill them if they are not chasing him by stepping over them while he is casually walking as explained above in B under the first opinion.]
One may kill creatures which pose danger in the following scenarios:
1. If the creature is definitely lethally dangerous, [which means that their bite always kills] then one may kill it in any form [in order to neutralize the threat], even if it is not chasing after a person.
2. If the creature is not definitively lethally dangerous but at times it can be lethal and at times not then it is permitted to kill them if either a) they are chasing after oneself, or it is not chasing after oneself but b) one kills it by stepping on it in a way that he makes it appear as if he were in the midst of a casual walk, and it thus appears to the bystander that he did so unintentionally.
3. Creatures which never kill but can cause bodily injury [as opposed to just mere pain] then if they are chasing oneself, they may be killed in any way. If they are not chasing after oneself, then one is allowed to kill them through casually walking on them, as explained above, although with these creatures, if it is possible to guard oneself from them as well as to warn others, then every meticulous person should refrain from killing them.
In short: One may always kill a creature that is chasing after oneself if it causes bodily damage as opposed to mere pain. If it is not chasing after oneself then one is to kill it casually, with exception to a case that the creature never poses danger to life, in which case one is only to kill it if he and others cannot beware from it.
A scorpion sting:
Is dangerous and one may desecrate Shabbos for it. A known cure is to capture the scorpion, kill it and fry it and then place it on the wound. This thus may be done even on Shabbos.
If one finds a snake on Shabbos and is unsure as to its level of danger, may he kill it?
Seemingly yes. Vetzaruch Iyun!
If a snake is hissing at a person is it considered as if it is chasing after him?
7. The prohibition to kill insects which cause mere pain even in the midst of a bite:
It is permitted to only trap a flea which is in the midst of biting oneself, however, to kill it is forbidden according to all opinions even if it’s on one’s flesh and is in the midst of biting him.
The reason for this is: As due to mere pain [the Sages] only permitted trapping [it] being that it is not a species which is commonly trapped and thus trapping it is not considered a [Biblically forbidden] action at all, however killing it is a complete [Biblically forbidden] action. [Now although] it is not done for its own use in which case there are opinions which say that one is exempt [from liability] on doing so, nevertheless [even according to them] it is Rabbinically forbidden and was not permitted to be done [in order] to prevent mere pain being that its prohibition is rooted in the Biblical [prohibition], meaning if [this same act] were to be done for its own use [in which case it would be Biblically forbidden].
May one squeeze the insect to weaken it? [Furthermore] even to squeeze it with one’s fingers to weaken its strength so that it not return to him is forbidden because of a decree that one may come to kill it. Rather he is to take it in his hand and throw it away.
It is forbidden to squeeze an insect, even if it is in the midst of a bite, as he may come to kill it which is forbidden in all cases, even if the insect is in the midst of a sting.
8. Killing spiders:
Those people who kill spiders on Shabbos (that are called shafin) need to be rebuked being that [spiders] do not cause bodily damage, and although there is worry that it may fall into ones food [and become lethal], nevertheless [it is forbidden to kill them] as this is not common [to occur], as well as that it is possible to cover the foods, and that also it is only one in a thousand that is lethal in food. Furthermore, even if it did carry a worry of danger [the Sages] only permitted killing it through casually trampling on it.
May one kill spiders?
No, they are not deadly and do not cause bodily harm.
May one kill a tarantula?
If the tarantula causes bodily damage, then it may be killed following the rules mentioned above. If it does not cause bodily damage, and merely causes great pain then it may not be killed.
May one remove cobwebs on Shabbos?
Some Poskim imply that it is permitted to break cobwebs on Shabbos, and doing so does not involve the Muktzah or destroying prohibition, or any other prohibition. Other Poskim, however, rule that cobwebs are considered Muktzah, just like earth and twigs and other waste. Accordingly, they may only be removed on Shabbos with an irregularity/Shinuiy [such as using ones elbow or feet]. Alternatively, if they have become repulsive to oneself, or to the guests in the room, then they may be removed even regularly. Other Poskim, however, rule that one is to completely avoid breaking or removing cobwebs that are attached to a wall altogether, as perhaps doing so transgresses the “uprooting an item from its place of growth” prohibition, or other prohibition. Practically, one may be lenient in a time of need to move the cobwebs in the method stated above. Nevertheless, in all cases one must beware not to kill the spider in the process.
9. Being cautious not to trample on ants and other non-dangerous creatures:
Species of crawling creatures which do not cause injury such as ants and the like, is forbidden to trample them even if one does not intend to kill them [in doing so] but it is inevitable. [Thus] one must beware of [stepping on] them in areas where they are commonly found.
May one step on ants while walking?
This is forbidden being that they will inevitably be killed, and thus one must take caution when walking near areas which he knows contains insects.
|Question: [Thursday, 10th Shevat 5781]
Dear Rabbi, these past Shabbos our city got attacked by a swarm of flying ants and they are literally all over the place. I stared at the ground when walking home from shul and saw hundreds of dead ants which were stepped on by people. My question is as follows: How careful must one be to not step on the ants while walking, and if it is not possible to avoid stepping on them is it forbidden to walk around on such a Shabbos?
Indeed, this is a serious halachic problem, and if in truth it is not possible to walk around without stepping on them then it is forbidden to walk outside on such a Shabbos. The same would apply in any case that there is an army of ants outside, of which it is not possible to bypass them without killing them, that it would be forbidden for one to cross that area with the ants even on the expense of staying home all Shabbos, and not going to shul. Thus, although one is not generally required to look on the ground when he walks outside on Shabbos to make sure he doesn’t step on any bugs, in the above case that one is aware of a proliferation of ants on the ground, he is required to look where he is walking and not step on any of the ants, and if one fears it will not be possible for him to do so then he should not walk outside this Shabbos. In the event that one already walked outside and is now surrounded by these insects and his only choice is either to stay put the entire Shabbos in that spot or walk forward and step on them, then the Poskim rule that one may be lenient to walk to his destination even if he will inevitably kill some of the insects although trying to make sure as much as possible to sidestep them and to walk on one’s tippy toes.
Explanation: Although it is a very clear ruling that is forbidden to kill any creature on Shabbos including ants, the question is raised regarding if this applies even if one kills it incidentally while walking and if therefore one must be careful in this matter. Now, while there is certainly room to argue that there should never be a prohibition involved in simply walking outside even if ants are killed in the process, so long as one does not intentionally step on them, and so rule some Poskim [due to it being considered a Shinuiy which is only rabbinical, and Eino Miskavein, and Eino Nicha Lei, and Derech Halicha], this is not the ruling of the Alter Rebbe, Mishneh Berurah, and that of other Poskim who rule that he must walk in a way that will avoid stepping on any insects, and they would thus rule that it is forbidden to walk outside in an area that one will inevitably step on insects and kill them. Nonetheless, there is still room to argue even according to the opinion of the Alter Rebbe that perhaps a prohibition only applies if by the very next step that one takes it is inevitable that one will step on an insect, in which case one may not take that next step and must go back or take a different route. However, if it is possible by one’s next step that he will sidestep the insect, then he is not required to look where he’s going even if he ends up truly stepping on insects and killing them as the matter was not a Pesik Reishei, as it was possible for him to step to the side of the insect and not kill it. [So indeed seems to understand the Piskeiy Teshuvos] However, there are two halachic pushback’s to this argument, 1) perhaps we take into account all the walking that one will do that day and if it is not possible for one to walk the entire day without stepping on an insect due to the infestation then it is considered a Pesik Reishei even though by each step that one takes, it is possible that one won’t step on the insect. 2) the Alter Rebbe rules that Safek Pesik Reishei is also forbidden and hence by every step that one takes in an area in which he sees that there is infestation, if he indeed ends up stepping on an ant, it is not considered a case of non-Pesik Reshei but rather of Safek Pesik Reishei which is still forbidden. This would be similar to the opinion who rules that one may not cover a vessel in which he sees that there is infestation in until he does a search and rescue mission to get rid of all of those bugs to avoid a trapping prohibition. Now, why do we not say according to all opinions that as soon as you got rid of all the visible bugs is no longer inevitable that you will end up trapping as perhaps there are no more bugs inside, and therefore it should be permitted? The answer is due to the fact that we rule that even a questionable Pesik Reishei is forbidden to be done. This is likewise the implied ruling of the Alter Rebbe who writes, “Species of crawling creatures which do not cause injury such as ants and the like, is forbidden to trample them even if one does not intend to kill them [in doing so] but it is inevitable. [Thus] one must beware of [stepping on] them in areas where they are commonly found.” This last statement implies that in areas that ants are commonly found one must intentionally beware to sidestep them even though it is possible that one will anyways end up sidestepping them while walking, and is thus not an actual Pesik Reishei. Thus, in conclusion, according to the Alter Rebbe, whenever one sees infestation on the ground he must be careful by each step that he takes that he does not end of stepping on an insect and he cannot simply avoid looking at the ground and claim that ignorance is bliss and that perhaps he walked in between the bugs. While I am aware that there are opinions who are lenient as already stated above, this would not be the ruling of the Alter Rebbe which all those who have accepted his ruling should follow. Nonetheless, in the event that one is already outside and is now surrounded by these ants we would be lenient to allow him to walk forward in the way explained above [side step, tippy toe etc] and not require him to stay put the entire Shabbos due to a great need of Kavod Shabbos and Kavod Haberiyos! Now, although there are other cases in which we forgive the person from moving from his area due to transgressing a Shabbos prohibition [i.e. walked past Techum], nonetheless, since this is a case of Eino Miskavein and Eino Nicha Lei of a rabbinical prohibition, therefore one may be lenient for Kavod Haberiyos.
Sources: See regarding the prohibition to step on ants while walking if will be inevitable: Admur 316:22; M”B 316:48; Elya Zuta 316:18 in name of Issur Viheter 58; Taz 326:2; Maor Hashabbos 4:14 footnote 136 in name of Rav Elyashiv Piskei Teshuvos 316:20; Sefer 39 Melachos by Rabbi Dovid Ribiat, page 892; http://halachayomit.co.il/en/ReadHalacha.aspx?HalachaID=3644 ;See regarding the subject of Safek Pesik Reishei: Admur 316:4; Kuntrus Achron 277:1; ; Taz 316:4; M”B 316:16; Biur Halacha 316:3 “Vilachen.” See regarding a cumulative Pesik Reishei: Admur 336:8; SSH”k 26 footnote 67 and 69; Piskei Teshuvos 336:7; See regarding the subject of Lo Nicha Lei: Admur 316:3 regarding bees; 316:4 and 320:24; 1st opinion in Michaber 320:18; Aruch Erech Sever, brought in Tosafus 103a; P”M 321 M”Z 7 and 511 M”Z 8; Chemed Moshe; Nehar Shalom; Shaar Hatziyon 658:6; Terumos Hadeshen, brought in M”A 314:5; Shaar Hatziyon 316:21; See Beis Yosef brought in Taz 316:3; see regarding that stepping casually is considered a Shinuiy: Admur 316:13; M”B 316:48
It is only allowed to kill a creature if:
1. It is a spontaneous creation not created from earth such as lice. [However, regarding other spontaneous creatures, see Q&A above] 
2. One is doing so to prevent himself from danger as was explained in Halacha 6-See there.
May one spray pesticide in his house if insects have become a nuisance to him?
Some Poskim rule it is forbidden to spray pesticide, as in addition to it being Muktzah being that it is not edible, and that it initially creates a repulsive area of dead insects which one will then move, it also inevitably kills insects while spraying and is thus forbidden. Other Poskim, however, rule it is allowed to spray in a different direction then the bugs, as long as one leaves a door or window open, as in such a case it is no longer inevitable to kill them. According to this opinion, it is permitted to spray it on one’s clothing and does not contain the prohibition of “making a new smell” being that it is not made to give a new smell.
May one place poison on the floor to kill roaches and mice on Shabbos?
Some Poskim rule that one may not do so, as although this form of killing is only a “Grama” nevertheless as said above the poison is Muktzah. However other Poskim rule that it is permitted. However, regarding a trap-see above Chapter 1 Halacha 4
May one place on himself a spray that has a bad smell and will cause the insects to leave?
If doing so will not kill any insects, then it is allowed. One may likewise smear the substance on his body.
If there are insects in one’s toilet may he flush it on Shabbos after using it?
If not doing so will cause a repulsive situation for people, then one may flush it.
May one wash bugs off of a fruit or vegetable?
One may do so even initially in order to eat right away, as it is considered like peeling off the peel of a food which is allowed to be done in close proximately to the meal. To note however that it is forbidden to wash the bugs off with salt water or vinegar and other liquids which kill the insects, due to the killing prohibition on Shabbos.
May a Mosquito zapper be turned on before Shabbos?
 Admur 316:13; Mishneh Shabbos 73a
 A type of animal with a unique colored skin
 Admur ibid; Smag 65
The Chilazon: Tzaruch Iyun as for why the Chilazon was not mentioned here, despite it being mentioned in 316:1 regarding trapping, and in 316:20 regarding learning the source that all the animals killed must be from male and female union. Perhaps though one can say that only those animals which are actually slaughtered are considered a Melacha in the legal sense, as an action must be done to actually kill them. This is in contrast to a fish which merely needs to be removed from the water, and no action of killing need be done.
 Admur 316:13; M”B 316:38
 Admur 316:14; Michaber 316:8; Mishneh Shabbos 107a; Rashi and other Rishonim on Chulin 46a and Shabbos 107a; M”A 316:14 in name of majority of Mefarshim; Levush 316:8; Yerushalmi 7:2; Rabbeinu Tam Kesubos 5b; M”B 316:29; Biur Halacha 316:8 “Hachovel” in name of majority of Rishonim including: Rashi; Ramban; Rashba; Ritva; Meiri
Other opinions: Some Poskim rule the prohibition of bruising a creature, and causing its blood to spill, is not due to Shechita, but due to the prohibition of Dush/Mifarek. [Rambam Shabbos 8:7 brought in M”A and M”B ibid] Others rule it is due to dyeing. [brought in M”A ibid]
Prohibition of Mifareik: See Admur 328:54 who implies that making a wound it contains both the prohibition of Chovel and Mifareik.
 Admur 328:33
 Admur 316:15; Michaber 316:8; Braisa Shabbos 107b; Vetzaruch Iyun how causing a bruise is Biblically forbidden according to the opinion who exempts a Melacha Sheiyno Tzericha Legufo, as how is a bruise ever Legufo, as explained in C?
 Admur ibid; M”B 316:30
 Mishneh Berurah 316:32 explains that since their skin is soft like flesh therefore their blood vessels that have broken are quickly returned to their place. Thus according to this explanation, they do have skin, and it’s just a matter of whether their skin is soft or hard.
 Setimas Hapoksim as the above prohibition is only in reference to a Beis Din, or community, punishing or incarcerating an individual, and not to a parent who does so for educational purposes.
 Tzitz Eliezer 15:41 brought in Piskeiy Teshuvos 316:23
The trapping prohibition: There is no trapping prohibition involved in trapping humans. [Setimas Hapoksim in 339; Piskeiy Teshuvos 316:23] One may thus lock a child in his room if needed. [Tzitz Eliezer 15:41 brought in Piskeiy Teshuvos 316:23]
Other opinions: Some Poskim question that perhaps the trapping prohibition applies to a child. [Avnei Nezer 189:22 based on Tosafus Menachos 64a]
 Some Poskim suggest that perhaps giving lashes is Biblically forbidden because it may cause a wound, which is a Biblical prohibition, and is thus included in the Biblical prohibition against giving punishment. [Rambam 24:7 as explained in M”A ibid; M”A 278:1 in name of Turei Even 40 and Rashal regarding a fight that this applies even according to Rebbe Shimon who holds Eino Tzarich Legufa is exempt; P”M 339 A”A 3] However, in truth, perhaps it is only a Rabbinical prohibition, as it is a Melacha She’eiyno Tzarich Legufa and one has no intent to make a wound. [see Machatzis Hashekel on M”A ibid that he has no intent to make a wound; P”M ibid that the above Biblical prohibition only applies according to opinion of Eino Tzarich Legufa Chayav; Admur 316:16]
 Piskeiy Teshuvos 339:7
 Admur 316:16; See also M”B 316:30 which deals with the issue of Mikalkel, which is not dealt with here in Admur.
The three levels of a destructive Melacha: There are three levels involved in a destructive Mealcha. 1) Melacha Htazricha Legufa, which means that one is doing the destruction for the sake of using the destroyed parts for a certain purpose [i.e. to use the blood for one’s dog]. In such a case one is liable according to all. 2) Melacha Sheiyno Tzricha Legufa, which means that one has no need for the actual parts of the destroyed item, although the action was done for some other external purpose. [i.e. Killed creature to prevent damage] In such a case it is disputed as to if one is liable. 3) Mikalkel, this means that one has no need at all for the Melacha, and it serves no gain or purpose, even external. In such a case one is exempt according to all, although it is Rabbinically forbidden.
 Admur ibid; M”A 278:1 in name of Rashal; See also M”A 316:15
Other opinions: The Raavad and Rambam dispute whether one is liable for injuring an enemy and causing his blood to spill. [M”A 316:15; M”B 316:30] It seems from Admur ibid that in a case that one receives pleasure from seeing the actual blood, then it is considered Melacha Legufa according to all, and one is hence liable even according to the Raavad.
 There it explains that one who injures a person on Shabbos is exempt from paying damages being that he is liable for death.
 See M”A 316:15; M”B 316:31; Shaar Hatziyon 316:48; Biur Halacha 316:8 “Vehachovel”
 What’s the difference between the two cases of killing for the sake of preventing injury versus killing an enemy, as also in the former case one is quenching his fear by killing the creature, and is also accomplishing that the creature does not hurt him, so it also has a purpose and should be considered Legufa. Also, if someone hits and injures someone in self-defense is that considered Legufa? Vetzaruch Iyun!
 Admur 328:3; Mamar Mordechia, brought in M”B 316:30
Other opinions: Some Poskim rule that removing a tooth for medical purposes [or doing any bruise for medical purposes] is considered a Melacha Shetzricha Legufa. [M”A 316:15; 328:3; P”M; Chayeh Adam; M”B 316:30]
 Admur 316:20; Shabbos 107b; Michaber 316:9
 Admur 316:14
 Admur 316:16
 Admur 316:20
 Admur 316:15
 Admur 316:17
 Admur 316:20; Shabbos 12a and 107b; Michaber 316:9
Other opinions: The Gemara ibid brings the opinion of Rebbe Eliezer and Beis Shamaiy that one is liable on all creatures, even if it does not reproduce.
 Admur ibid; M”A 316:20; Rambam 11:2
The Mishneh Berurah adds the following: a) It is nevertheless Rabbinically forbidden [unlike the opinion of the Magid Mishneh brought in the Magen Avraham which holds here that it is completely permitted] and it is only by lice that the Sages completely permitted killing it because it was created from sweat or because it is repugnant.] b) It is only Biblically permitted if it grows while off the tree and after the food has spoiled. However, if it grew while on the tree or before the food has spoiled then it is included in the Biblical prohibition. [See Mishneh Berurah and Biur Halacha on Halacha 9] See Q&A below
 Admur ibid; Gemara ibid; M”B 316:38
 Admur ibid; Gemara ibid; Michaber ibid
 Admur ibid; Ran M”B ibid
 Admur ibid; Shabbos ibid; Michaber ibid
 Admur ibid; Michaber ibid; Rosh 1:29
Other opinions: Some Poskim rule it is permitted to check and kill lice even of clothing. [Rashi; Ramban; Ran; Ritva, Chaim Tzanzer, Elya Raba, brought in Biur Halacha 316:9 “Lo Yehargem”]
 Admur ibid [parentheses in original, in Mareh Mekomos of Admur it says “See Rosh Vetzaruch Iyun Gadol”; See Ketzos Hashulchan 122 footnote 6]; M”A 316:21; M”B 316:42; See Elya Raba; Chaim Tzanzer brought in Biur Halacha 316 “Lo Yehargeim”
Other opinions: Some Poskim rule one may not throw the lice in the water. [Elya Raba 316, brought in P”M 316 A”A 21]
 Admur ibid; Michaber ibid
 Admur 316:21; M”A 316:21
 Admur 316:20
 Admur 303:27
 Biur Halacha 316:9 “Mutar”
 The Rambam in Sefer Hamitzvos Lo Sasei 178 holds that so long as the insect was not created from spoiled waste, such as insects created in fruits of a tree, then it can reproduce. The Ramban however in his Hasagos Shiresh 9 argues that such an insect can never reproduce.
 Opinion of Admur: In the beginning of 316:20 Admur states that only if the creature is both created by a male and female and also reproduces do we say one is liable. This implies that if t either does not reproduce, or was not created by a male and female [even if it does reproduce] then he is not liable. However, In the middle of 316:20 Admur writes “Nevertheless [killing] the flea contains the [Biblical prohibition] of taking a life even though it is created from earth and does not reproduce” hence implying that only if the creature is both created spontaneously and does not reproduce, do we say it is exempt. Vetzaruch Iyun
 Rav Dessler in Michtav Eliyahu vol. 4 page 355, Opinion of Rav Yehuda Bril brought in Pachad Yitzchak “Tzeida”, and many other Poskim listed in Yalkut Yosef Vol. 4 chapter 316.
 Brought in Sharreiy Emunah chapter 43
There the Rebbe states the following rules regarding scientific studies that contradict the teachings of Torah:
1) Science is based on theories and not facts, and thus one cannot distort or change the simple interpretation of the words of our Sages which are the words of the Living G-d which states the absolute truth, based on conclusions developed from un-provable and merely theoretical hypothesis of a human.
2) However, when science has come to a conclusion based on an absolutely provable fact then within the allegorical sections of the Talmud there is room to interpret the sayings in deviation of their simple meaning.
3) However, when it comes to the legal aspects of the Torah then there is no room for deviation at all from its simple meaning, irrelevant to what scientific study has proven with human intellect, and thus the Halacha is to be taken literally for all matters. Regarding this specific issue the Rebbe there states that he has thoroughly investigated the topic of spontaneous generation while in Paris with the greatest professors in this field, and although there are studies which have showed that creatures which in the past were believed to have generated spontaneously in truth were reproduced through male and female, nevertheless they have no conclusive evidence that such a concept does not exist. Furthermore, there are many biologists which firmly believe that organisms can be created from inanimate items.
 Pachad Yitzchak 10 “Tzeida” p. 21; Sheivet Hakehasy, brought in Piskeiy Teshuvos 316 and Yalkut Yosef ibid
 Authors personal thoughts:
A question on the first opinion: If science has today “proven” that lice are reproduced through male and female then why do we not simply say that this is not the species of lice referred to by the Sages, and thus there is no contradiction and it is thus forbidden to kill the species of lice that does reproduce.
- Seemingly the answer to this question is that tradition-which is as authentic as Halacha- has it that these lice are the same lice referred to always and thus there is no room for compromise.
A question on the dissenting opinions and their scientific facts: To my knowledge studies have not proven that sweat does not take a pivotal role in the development and growth process of the egg while in the mother lice and after it has been laid. Perhaps then this is the meaning behind the saying of the Sages that the lice are created from sweat, and there is thus no proven contradiction to the saying of the Sages. If so there is no room at all to be stringent against the ruling of the Sages of all generations.
 Magen Avraham 316:20, based on Magid Mishna on Rambam 11:2
 Mishneh Berurah 316:41, based on Lechem Mishna ibid, and so is brought in Peri Megadim A”A 20.
 From fact a) omits the clear ruling of Magen Avraham that it is permitted. B) simply states that one is exempt as opposed to permitted as he writes by lice.
 Magen Avraham 316:20, however, see Peri Megadim ibid that questions this saying either way it should still be permitted being that the insects were not created from the earth. However, the Biur Halacha negates this proving clearly that insects which were grown within a fruit when attached are considered grown from the earth.
 Biur Halacha Leharga
 As all bugs that are created from fruit prior to deterioration are able to have offspring. [Biur Halacha ibid]
 From the fact that Admur mentions the wording of the Rambam which only mentions the allowance by spoiled fruits, and completely omits the ruling of the M”A that allows it when detached. Perhaps this is coming to teach that even when detached it is forbidden so long as the fruit has not yet spoiled.
 Admur 316:13; M”A 316:17; M”B 316:33
 Meaning that it has congealed and thus sticks to the finger and gets stretched out like gum.
 The reason it is not permitted due to Pesik Reishei: As Amira Lenachri was only permitted by a Pesik Resihei in which the Melacha is the result of the inevitable occurrence of a second action, such as to remove the pot from the coals which will cause the coals to fall. If, however, the Pesik Resihei is a result of the actual action performed by the gentile, then it is forbidden to ask a gentile.
 Levusheiy Serud
 There it discusses when a fish is considered to be trapped.
 Admur 316:13
 See M”B 316:33
 Admur 316:22; Michaber 316:10; Shabbos 121b
 Admur ibid; Michaber ibid; Shabbos ibid
 M”B 316:45 in name of Peri Megadim
 Shaar Hatziyon 316:72
 See Halacha 7
 Admur ibid; Michaber 316:10; Shabbos ibid in opinion of Rav Katina, as explained in Tosafus Beratzin
 Admur ibid; implication of Michaber ibid; Mordechai 402
 Admur ibid; M”B 316:44
 Admur ibid; M”B 316:48
 Admur ibid; Tosafus Shabbos ibid; Kesef Mishneh; M”A 316:23; M”B 316:44
 Rambam and Rebbe Yehuda
 Admur ibid; See Shabbos ibid “The spirit of the Chassidim are not pleasant with those that kill Mazikin, and the spirit of the Sages is not pleasant with these Chassidim”; Vetzaruch Iyun if one can trap it versus killing it, if he must do so to avoid a potential Biblical prohibition?
Ruling of M”B: In 334:85 and 340:1 the M”B rules that the main opinion follows the lenient opinion.
 See also 334:29; Kuntrus Achron 275:2
 Admur ibid; Implication of Ramban and Rashba
 Admur 316:22
 Admur 328:6, Ketzos Hashulchan 137 footnote 1. See also chapter 316
 Biur Halacha
 Admur 316:19; Michaber 316:9; Beis Yosef; M”B 316:44; Biur Halacha 316:9 “Veassur Lehargo”
 Admur ibid; Michaber ibid; Biur Halacha 316:9 “Lo Yimalelenu”
Other opinions: Some Poskim rule one may squeeze the insect to weaken it. [Elya Raba, brought in Biur Halacha ibid]
 Admur 316:23
Other opinions: Some Poskim rule one may casually kill a spider on Shabbos. [P”M] The Biur Halacha ibid negates his opinion.
 Some spiders are lethal when eaten
 Admur 316:23
 Despite their often-threatening appearance and reputation, no tarantula has been known to have a bite that is deadly to humans. In general, the effects of the bites of all kinds of tarantula are not well known. While the bites of many species are known to be no worse than a wasp sting, accounts of bites by some species are reported to be very painful and to produce intense spasms that may recur over a period of several days; the venom by the African tarantula Pelinobius muticus also causes strong hallucinations. In all cases, it is prudent to seek medical aid. Because other proteins are included when a toxin is injected, some individuals may suffer severe symptoms due to an allergic reaction rather than to the venom. Such allergic effects can be life-threatening.
 See Piskeiy Teshuvos 250:9
 Implication of Leket Yosher “One time a spiders web was made on the faucet and he [the Terumas Hadeshen] said that it is permitted to break it on Shabbos.” [Nonetheless, it is still possible to interpret the allowance only to a vessel, such as a faucet, and not to a wall. However, the Betzeil Hachachmah 5:18 and Rav SZ”A in SSH”K 23 footnote 34 clearly rule that there is no destroying or Toleish prohibition involved by cobwebs, and hence when this is joined with the opinion of the Leket Yosher that it also does not contain a Muktzah prohibition, then it is allowed in all cases to be removed or broken on Shabbos]; See Admur 328:53 [based on 1st opinion in Michaber 328:48; Rokeaich 70; Kol Bo 31] that one may treat a bleeding wound through wrapping a spiders web around it, thus proving that it is not Muktzah. See, however, Tehila Ledavid 328:79 that for the sake of relieving pain, the Sages permitted the moving of Muktzah. However, from Leket Yosher ibid, it is implied that it is permitted even not for the sake of relieving pain, as well as that no such allowance is recorded in Admur regarding Muktzah, and on the contrary, he explicitly mentions the Muktzah prohibition even in a case of pain. [See Admur 308:56 regarding placing raw cloth materials on a wound and 328:51 regarding eye pain] Thus, one must conclude that according to the Poskim ibid, cobwebs are not Muktzah on Shabbos. On the other hand, perhaps one can establish the case to be referring to cobwebs that were already prepared before Shabbos. Vetzaruch Iyun.
 Mor Uketzia 328; Tehila Ledavid 328:79; Pesach HaDvir 328:11; See Kaf Hachaim 328:270; Orchos Chaim Spinka 328:36
 Betzeil Hachachmah 5:18; Regarding the allowance of moving Muktzah with a Shinuiy-See: Admur 308:15; 311:15; 276:9-10; 266:19
 SSH”K 23 footnote 34 in name of Rav SZ”A; Beir Moshe 37; In such a case they may be removed even normally, as then they are considered a Graf Shel Reiy. [SSH”K 23 footnote 34 in name of Rav SZ”A]
 Yifei Laleiv 328:3 leaves this matter in question as to if its considered a prohibition of removing an item from its place of growth; Kaf Hachaim 328:270; SSH”K 23:9
 Betzeil Hachachmah ibid and Rav SZ”A ibid both argue that this prohibition does not at all apply; Piskeiy Teshuvos 250:9
 See Admur 316:23; M”A 316:23; M”B 316:48; Biur Halacha “Veafilu”
 Admur 316:22; M”B 316:48; Elya Zuta 316:18 in name of Issur Viheter 58
 Admur 316:22
 Admur 316:20
 Piskeiy Teshuvos 316
 Ketzos Hashulchan 122 note 11, and other Poskim
 So rules also Shvus Yaakov 2:45
 Bear Moshe 2:23
 There he explains that from the letter of the law it is permitted to spray it even if the insects have nowhere to escape, so long as one does not directly spray it on them, as in case of pain one may be lenient by a mere Grama by a case of pain.
 Ketzos Hashulchan 122 footnote 11, as rules Shvus Yaakov 2:45
 Beir Moshe 2:23
 Ketzos Hashulchan chapter 138 footnote 31
 Minchas Yitzchak 10:27; Sheivet Halevy 7:94; Piskeiy Teshuvos 316,
 The reason: based on the fact that anyways flushing the insects together with the feces is an indirect act which one has no intention to do and is thus allowed in pressing times.
 Shabbos Kihalacha Vol. 2 p. 134-136
 So rules Ketzos Hashulchan 125 footnote 16
 Shabbos Kihalacha Vol. 2 p. 199