Is it permitted to cause pain or kill living creatures?[1]

It is Biblically forbidden to actively[2] cause pain to any[3] living creature [for no justifiable reason, as will be explained].[4] [It goes without saying that one may not kill a creature for no justifiable reason.[5]]

If the creature is a nuisance:[6] If the creature is a nuisance[7] to a person then it is permitted even to kill it, even though this will put the creature through pain, [and certainly one may inflict pain onto it, without killing it, in order to remove the nuisance[8]]. Thus one may poison a dog that is a nuisance.[9]

Using the body of the creature for a purpose:[10] It is permitted to kill any creature if one needs to use the creature for medicinal purposes, or for other purposes that serve man.[11] The prohibition of Tzaar Baalei Chaim does not apply in such a case. It is thus permitted to kill an animal for the sake of feeding its meat to dogs.[12] [It is however forbidden to kill or cause pain to an animal even for a purpose, if one can easily fulfill the purpose through other means to the same level of quality.[13]]

May one pluck a feather from a live goose?[14] If one has another feather available, then it is forbidden to do so. If one does not have another feather available, it is permitted to do so, although the custom is not to do so due to it being an act of cruelty.

Midas Chassidus and Kabala: The Arizal[15] was careful never to kill any living creature, even if it was a mere insect and was a nuisance. This was likewise the custom of the Rebbe Rashab.[16] Some[17] state that one should never directly kill a creature, even if it causes pain, unless it can cause real injury, such as a snake, and one is rather to indirectly cause them to die, such as through poison. It is thus a Midas Chassidus not to directly kill a living creature with one’s hands even if it is a nuisance, and is hence permitted to do so from the letter of the law. [If however the indirect killing will cause the animal more pain, than seemingly it better to kill it directly.[18]] The Gemara[19] states that Rebbe Yehuda Hanaasi experienced suffering due to a certain incident that involved Tzaar Baalei Chaim, even though it was permitted according to Halacha and it was then removed after he showed mercy to animals.[20] Q&A May one kill insects that infest one’s food?[21] Yes. May one kill mice and rodents in one’s house?[22] Yes. Some[23] write there is no Midas Chassidus involved in being stringent not to do so, although it is best to avoid killing it directly with one’s hands and one is to rather use a trap or poison and the like. However based on the Arizal it is a Midas Chassidus not to kill the creature. May one kill bothersome insects such as mosquitoes and flies and the like?[24] Yes. Some[25] write there is no Midas Chassidus involved in being stringent not to do so. However based on the Arizal it is a Midas Chassidus not to actively kill the creature. The Rebbe Rashab would not kill the mosquitos, but would rather brush them away with his hand.[26] May one kill spiders that are in one’s home? Yes.[27] Spiders are viewed as Kelipa according to Kabala, and interfere with the Shalom Bayis of a home.[28] Some[29] Gedolei Yisrael were particular to actively kill spiders. It is a Mitzvah to clean one’s house from cobwebs [and spiders[30]] on Erev Shabbos.[31] May one kill hair lice? Yes.[32] However based on the Arizal it is a Midas Chassidus not to actively kill the creature.[33] May one kill a creature that is suffering? See next.

Maaseh Shehayah: Rebbe Yehuda Hanaasi:[34] The great Tana, Rabbeinu Hakadosh was once approached by a sorrow calf whose turn it came to be slaughtered. The somber calf understood its fate and entered its head into Rebbe Yehuda’s cloak and began crying. Rebbe replied to the calf “Go ahead for the slaughter, it is for this reason that you were created”. The Heavenly courts declared “Since you did not have mercy on this calf, you will receive suffering.” This suffering came to end after the following episode: Rebbe’s maid was sweeping the house and found a family of baby rats inside [which she desired to harm]. Rebbe Yehuda told her not to do anything to them, as “Hashem is merciful on all his creatures.” The Heavenly courts this time declared “Since you had mercy on these rodents, we will have mercy on you.”