Can I set a trap for Shabbos?

QUESTION

Are you allowed to set a trap before Shabbat and have it kill the animals on Shabbat?

There are two parts to the question

One is regarding setting Traps for Shabbos and second is if one can cause the animals to die on Shabbos

May I set up a trap  to catch pests on Shabbos?

One of the 39 melachos is trapping (tzeidah), since in the construction of the mishkan, they trapped animals for their hides and the chilazon that was used for dyes. Min haTorah, the prohibition applies only to species that people commonly trap for their use (e.g. deer, rabbit etc.). Midrabanan, however, it is prohibited to trap even species that are not commonly trapped (e.g. flies, insects), and even if one has no purpose in mind and plans to set it free immediately thereafter.¹

Setting a trap on Shabbos for an animal to be caught immediately is prohibited min haTorah, yet if the trap will only catch the animal later on Shabbos, it is prohibited midrabanan as the sin is not transpiring right away .²

What is the halacha regarding mice traps?

Some poskim consider mice to be a species that is not commonly trapped for a purpose, and thus constitutes a “double derabanan” (i.e. twice removed from the issur de’oraisa of trapping), in which case it would be permitted to transgress  in cases of great need.³  however other poskim, including the Alter Rebbe, prohibit setting a mousetrap on Shabbos. The reason  is probably because mice are sometimes caught for a purpose (certain types in certain places).⁴ Another possible explanation is that trapping a mouse is not considered a “great need” and therefore it isn’t sufficient reason to permit even a “double derabanan.”⁵ However, if the mice are frightening the people in the home, one may put out a trap that doesn’t catch the mouse right away  .⁶

May I set up a trap on Friday   to catch pests on Shabbos?

There is discussion between Beis Shamai and Beis Hillel whether one’s utensils must rest on Shabbos, and the halacha follows Beis Hillel that it is generally permissible to set up his utensils before Shabbos to do work on Shabbos for him therefore although there is halachic issue with setting the trap on Shabbos proper as explained nonetheless Setting a trap on Friday to catch pests on Shabbos is allowed, since it is permissible for one’s utensils to continue to do work for him on Shabbos.⁷

If a pest has been caught on Shabbos, it is muktzeh and may not be moved in the regular manner unless it is in a public location and poses a disgust to those nearby. In this case, it has the status of graf shel rei (a muktza item that poses disgust) which may be moved away to create a peaceful environment.⁸

What is the halocho if the trap causes the animal to die?

Killing a animal is called “nitilas neshomo” is part of the melacha of “shochet” and it doesn’t matter if blood actually comes out , therefore one may not poison a animal or insect on Shabbos.9

However one is allowed to set the poison before Shabbos as explained by the melacha of trapping.

[1] גמ’ שבת דף ק”ו ע”ב. שוע”ר סי’ שט”ז ס”א וס”ד.

2 מג”א ס”ק ט’ שוע”ר סי’ שט”ז ס”ו.

3 ראה ס’ הליכות שבת ח”א פי”ז ס”ז.

4  (שהם מהשמונה שרצים שיש להם עור) וראה חיי אדם כלל ל’ ס”ז. ובמיוחד שמשתמשים בהם למחקר, רק שיש לדון שלא כל המינים ניצודים למחקר.

5 שיעורי הלכה למעשה להרשד”ב לוין שליט”א סי’ ל”ד עמ’ רט”ו.

6פסק”ת סי’ שט”ז סק”ט וזה בצירוף כמה דברים א. מלאכה שאצל”ג ב. מקום צער ג. ספק אם עכברי בית הם מינו ניצוד ד.צידה באופן כזה הוא אסור רק מדרבנן.(והסכים לזה מו”ר הגר”מ אהרון שליט”א).

7שוע”ר או”ח סי’ רנ”ב ס”א.

8 ראה שוע”ר סי’ ש”ח סע”ח וסע”ב וראה גם פסק”ת סי’ שט”ז הע’ 72.

9 ראה ארחות שבת פי”ד סכ”ט. וראה שם בהערה שנחבט בזה.