1. Although, as we have learned, killing living creatures can violate the melachah of netilat neshamah, Chazal made an exception for lice. The majority opinion among Chazal, which is the accepted one, is that lice did not reproduce in the same manner as other creatures, and therefore killing them was not included in this melachah. The Shulchan Aruch accordingly rules that one may kill lice found in one’s hair on Shabbat (O.C. 316:9).

2. Contemporary poskim disagree about whether this ruling still applies, given our knowledge that lice reproduce by laying eggs. Some prohibit killing lice today, based on the possibility that the lice described by Chazal differed from those found today (R. Nebenzahl, in the B’yitzchak Yikarei edition of Mishnah Berurah, citing R. Shlomo Zalman Auerbach). Others permit killing lice, maintaining that the halacha remains unchanged (R. Aryeh Carmell; Yalkut Yosef, O.C. 316:10).

To sign up for the daily halacha via WhatsApp or email, click here.

Dedicated by Fran Broder as a zechus for everlasting peace in Eretz Yisrael in the merit of learning Hilchos Shabbos.