Navigating Jewish Law: What’s Permitted on Shabbat When It Comes to Insects and Pets?

From ant infestations to aquarium care, questions about animal-related activity on Shabbat often come up. Here’s a user-friendly breakdown of the halachic (Jewish legal) guidelines, explained clearly and practically for everyday situations.

Gently Sweeping Ants Outside on Shabbat

Is it permitted to sweep ants from your kitchen to the outside of your home on Shabbat?

Yes. Gently sweeping ants outdoors is allowed, as long as it’s done carefully and without the intent to kill them. Since it’s not certain they’ll die in the process, and your goal isn’t to harm them, it’s permitted. However, for larger insects that cause distress and can’t be swept away, you may pour a small amount of water or spray repellent around—but not directly on—them. This is based on rulings by Rabbi Shlomo Zalman Auerbach (Shmirat Shabbat Kehilchatah 25:29), following halachic principles from the Shulchan Aruch and Rema (Orach Chaim 334:22). The idea is that when there is a pressing need, it is permitted to perform an indirect action (known as grama) when the outcome is not your main goal.

An effective and halachically preferable alternative: ground cloves or clove oil. When sprinkled near ants, they typically flee back to their nests. So if cloves work, there’s no halachic basis to use insecticide, even around the bugs, since eliminating them would no longer be considered a pressing need.

Walking Where Insects Are Present

What if you're walking on the street and see a trail of ants on the sidewalk? Can you walk through?

If the ants are small and it’s unclear whether your walking will kill them, it's likely permitted, though at least one ant may die. This is close to what's called in halachic terms a pesik reisha (an inevitable but unintended outcome). Rabbi Ovadia Yosef permitted this based on the view of the Ritva (Yechaveh Daat 4:34). Still, the Biur Halacha (Orach Chaim 317:1) and other major sources take a stricter approach and prohibit it.

If the ants are large and will certainly be crushed, then you should not walk there unless there’s no other way into your home. In such a case, since it’s a rabbinic prohibition and involves kavod habriyot (human dignity), it is allowed.

If you need to walk through the area for an important reason, like getting to synagogue or a Shabbat meal, though not a basic necessity or something that preserves human dignity, you should walk in an unusual way (e.g., on your heels). Doing so is enough of a change to make it permissible according to all opinions (Mishnah Berurah 316:5, 321:57).

Feeding Fish on Shabbat

Can you feed your fish on Shabbat? What if their food consists of live feeder fish?

You're allowed, and even required, to feed animals that depend on you. This is both a mitzvah (commandment) and a halachic obligation (Shulchan Aruch 324:11; Mishnah Berurah 324:29). So if you normally feed your fish small, non-living food, there’s no problem feeding them as usual.

However, if your fish typically eat live feeder fish, feeding them on Shabbat is not allowed. This would involve the prohibited categories of tzayid (trapping) and netilat neshamah (taking a life), which are not permitted even for the sake of feeding animals.

Moving Pets on Shabbat: Hands vs. Leash

The Shulchan Aruch (Orach Chaim 308:40) rules that animals are muktzeh (halachically set aside not to be used on Shabbat), meaning you can’t move them with your hands. Yet elsewhere (Orach Chaim 305:5), it says you can walk an animal with a leash.

Why the difference?

When you move an animal by leash, you're not fully lifting or carrying it. It’s indirect movement (tiltul min hatzad). If the reason is for the animal’s own benefit, such as preventing harm or escape, this is permitted, especially when the animal depends on you and may suffer otherwise.

However, simply picking up an animal by hand, especially if it’s not for its benefit, remains forbidden. The more lenient ruling applies only when the leash is used for the animal's well-being, not for the owner's convenience.