Stealing:[1]
A child must be reprimanded for stealing, and it is proper for a Beis Din to smite the child for doing so in order so they do not accustom themselves to stealing. It is likewise proper for every individual to reprimand the child and prevent such behavior.
[1] Rambam Geneiva 1:10; Maggid Mishneh Geneiva 1:10 in name of Rambam; Bach 343 in end; Beir Hagoleh C.M. 349:5; Chayeh Adam 66:5; P”M 343 M”Z 2; M”B 343:9 in name of P”M and other Achronim; Kaf Hachaim 343:26; Piskeiy Teshuvos 343:2 and 6; Encyclopedia Talmudit ibid p. 200