Would the Bnei Yisroel have been permitted to trap arov on Shabbos?

Trapping on Shabbos

Question #1: Non-kosher Trapping

“Is it prohibited min haTorah to trap a non-kosher animal on Shabbos?”

Question #2: Watch your Trap!

“Can someone violate the melachah of trapping by closing the door of his house?”

Question #3: Anesthesia

“Is it permitted to anesthetize an animal on Shabbos?”



One of the 39 melachos forbidden on Shabbos is tzad, trapping. Although it might seem that this is an easy melachah to define, we will see that it presents some interesting issues. For example, some instances that we would never call “trapping” in English violate the melachah of tzad, and many things that we might consider to be trapping do not. For example, if a deer happens to wander into your house, and you close the door so that it cannot get free, you have just violated the Torah prohibition of tzad. On the other hand, if you close the door of a large cage with a small bird inside, you have not violated the melachah of tzad min haTorah. Tzad requires that the animal or bird is now easily usable, which is not the case of a small bird in a big cage. How one violates the melachah of tzad min haTorah might even vary from species to species, depending on how easy it is to catch.

Not all melachos are created equal

Let us examine another curiosity about trapping. Tzad is not a typical melachah. Most melachah actions make some type of physical and/or chemical change on their object, such as what happens when one cooks, sews, plants, or builds. Yet, tzad does not cause any kind of chemical or physical change to the animal that is caught. It is therefore among the minority of melachos that do not create any physical change. There are only a few other melachos in this category. A similar melachah is hotza’ah, carrying, which involves changing an item’s location, but no alteration to the item itself.

On the other hand, tzad creates a functional change – one makes the animal accessible to humans, whenever one may need it. Since the purpose of trapping is to harness a living creature, so that mankind can now access it, tzad can be viewed as a type of “acquisition” that makes the animal “usable” (Shu”t Avnei Neizer, Orach Chayim 189:7; however, see Biur Halachah 316:2 s.v. oh choleh, who may disagree).

Trapped species

The Torah prohibition of tzad is violated only when one traps a creature that is normally hunted by mankind (Shabbos 106b), meaning that people use its food or hide, or extract from it a medicine (Shabbos 107a) or dye (Shabbos 75a). An animal that meets these requirements is called bemino nitzod, literally, a species that is trapped. Catching an animal of a species that is not usually trapped or used by mankind, which is ein bemino nitzod, is not prohibited as a melachah min haTorah, but only because of rabbinic prohibition. Therefore, catching an animal whose species has no commercial value does not violate tzad min haTorah.

Non-kosher trapping

At this point, let us discuss the first of our opening questions: “Is it prohibited min haTorah to trap a non-kosher animal on Shabbos?”

If this is a type of animal whose hide is used, or from which either a dye or medicine is extracted, trapping it is prohibited min haTorah. According to the Chazon Ish (Orach Chayim 50:4 at end), someone who catches an animal to become a pet also commits a Torah violation of tzad. In his opinion, this use qualifies as bemino nitzod. On the other hand, what is the halachah if an animal is non-kosher, but non-Jews trap it for food? Is bemino nitzad for food limited to whether Jews eat it or not?

This appears to be the subject of a dispute between the rishonim, since Rashi (Shabbos 106b s.v. Hagizin) implies that trapping an animal for food is prohibited min haTorah only when it is a kosher species. On the other hand, the Ritva (Shabbos 106b) states explicitly that trapping a non-kosher species on Shabbos because a gentile intends to eat it is prohibited min haTorah – the fact that gentiles consume the non-kosher species qualifies it as bemino nitzod.

Catching mice

Early halachic authorities prohibit setting up a mousetrap on Shabbos (see Piskei Tosafos, Shabbos 17b, #62;  Magen Avraham 316:9). However, this does not mean that catching mice on Shabbos violates a Torah prohibition – it might be prohibited only miderabbanan. This is because it is unclear whether mice are considered bemino nitzod. If they are considered bemino nitzod, then catching them could sometimes be prohibited min haTorah. If they are not considered bemino nitzod, catching mice is prohibited only because of a rabbinic ruling.

Why would mice or rats be considered bemino nitzod? Although cats catch mice and rats for food, people in the western world are not interested in mice or rats for their food, leather or any other purpose. And the fact that a cat considers it bemino nitzod should not affect halachah.

However, one major authority, the Chayei Odom (30:7), rules that rats are considered bemino nitzod, since the hide can be used for leather, albeit of poor quality. In addition, according to the above-mentioned opinion of the Ritva, in a country where people eat rats, they qualify as bemino nitzod. Therefore, in China, where barbecued rat is a delicacy, it is bemino nitzod, according to the Ritva.

Catching lions

We will now move our discussion from the minute to the massive, from mice to lions. A lion is certainly considered bemino nitzod, since the hide would definitely be used, and, therefore, someone who successfully trapped a lion would violate tzad. However, lions are fairly powerful, so one would violate tzad only if it was, indeed, caught. The Gemara teaches that if a lion wandered into your house, closing the door does not constitute a Torah violation of trapping, since the lion will be able to break free. It is not considered tzad because one has not completed trapping it. One violates tzad for trapping a lion only by catching it in a cage or something similar that can keep it restrained (Shabbos 106b). Presumably, anesthesizing it or any other animal involves a melachah activity of tzad, since it is now “captured,”  and one can move it into an appropriate enclosure while the animal is anesthesized.

Thus we can now address the third of our opening questions:

“Is it permitted to anesthesize an animal on Shabbos?”

It seems to me that, if the animal qualifies as bemino nitzod, this is prohibited min haTorah, and, if it does not, it is prohibited miderabbanan.

Catching bees and wasps

Having discussed both mice and lions, let us move from land creatures to flying ones. Catching bees on Shabbos is prohibited because of a rabbinic prohibition, but not min haTorah (Beitzah 36b), for an interesting reason. Most beekeeping businesses pay their bills either by renting the bees for pollination of crops or by selling the honey. In either way, bees are “used” commercially by allowing them to roam wild – thus, they are never really “trapped” for use by man (Shu”t Avnei Neizer, Orach Chaim #189:21).

In an article I wrote entitled “Wanted Dead or Alive,” I discussed whether on Shabbos one may catch creatures, such as wasps and mosquitoes, that most of us consider a nuisance.

Catching itself

The Gemara (Shabbos 107a) describes what seems to be a very strange case. If a bird flies into your sleeve or garment on Shabbos so that it is now effectively caught, one is not required to release it. In this instance, the bird is considered to have trapped itself, and there is no requirement to let it go. However, one must be careful not to move it directly on Shabbos, since it is muktzeh.

Not always caught

Sick animals

On the other hand, catching a deer or any other animal that is sick, lame or injured to the extent that it is unable to flee does not involve a Torah prohibition of tzad. Since the animal can be obtained with little effort, it is considered already caught and already available for man’s possession (Tosefta, Shabbos Chapter 13:4; Gemara Shabbos 106b; Rambam, Hilchos Shabbos 10:24). Similarly, it is not prohibited min haTorah to catch a newborn animal that is not yet strong enough to flee (Beitzah 24a). It is also not a Torah prohibition to catch a snail, since they are so slow that they are considered caught (Tosafos Rid, Chagigah 11a).

Domesticated animals

There is no melachah min haTorah involved in catching an animal that is already cultivated, such as domesticated chickens or geese (Shabbos 107a; Rambam, Hilchos Shabbos 10:24). However, if the animal breaks free, catching it is prohibited miderabbanan. This is also germane to catching a caged pet that broke free. What can one do if one’s favorite parakeet escaped from its cage on Shabbos? Because of space considerations, we will need to leave the details of this topic for a different time (see Magen Avraham 316:26).

Locking the door

With this background, we can explain some of the following laws concerning meleches tzad. The Mishnah (Shabbos 106b) states that if a deer entered a house, it is prohibited min haTorah to close the door, because this traps the deer. Similarly, it is prohibited min haTorah to sit in the open doorway, because doing so also traps the deer (Mishnah Shabbos 106b). However, once someone is blocking the deer’s excape path, it is permitted for a second person to position himself in such a way that the deer will remain trapped even after the first person gets up (Shabbos 107a). To quote the Rambam, If the first person sat in a way that he closed off the deer’s exit, and then a second person sat next to him, even if the first one later gets up, the first person desecrated Shabbos and the second one did not do anything. He is permitted to remain in his place until Shabbos is over and then seize the deer (Hilchos Shabbos 10:23). The reason why this is permitted is because once the first person caught the deer, it is permitted to keep it captured (Mishnah Berurah 316:23, 24).

Similarly, if someone closed the door and thus caught the deer, a second person may now lock the door to make sure that no one mistakenly opens the door, which will free the deer (Rav, Shabbos 106b; Rema, Orach Chayim 316:5). These acts are permitted even miderabbanan.


Rav Hirsch (Shemos 35:2) explains that whereas other melachos demonstrate man’s mastery over the physical world, carrying demonstrates his mastery over the social sphere. Most melachos show man’s mastery over the world by the way man changes them. In the case of tzad, it is man’s showing mastery of the animal world by demonstrating his potential ownership. Rav Hirsch further notes (Shemos 20:10) that people assume that work is prohibited on Shabbos in order to make it a day of rest. He points out that the Torah does not prohibit doing avodah, which connotes hard work, but melacha, which implies purpose and accomplishment. Shabbos is a day on which we refrain from altering the world for our own purposes. The goal of Shabbos is to allow Hashem’s rule to be the focus of creation, by refraining from our own creative acts (Shemos 20:11). We thereby demonstrate and acknowledge the Creator of the world and all it contains.


Tzaar Baalei Chayim

In Chutz La’aretz, this week parshas Balak is read, and in Eretz Yisroel, this is one of the rare years when we read parshas Pinchas before the Three Weeks. Since both parshiyos include allusions to tzaar baalei chayim, I present:

Tzaar Baalei Chayim

Question #1: Scientific experimenting

“Are there halachic laws governing when and how one may conduct scientific or medical experiments on animals?”

Question #2: Licensed to kill!

“Are there any halachic concerns that I should know about becoming an exterminator?”

Question #3: Oversized rider

pony“On visiting day in camp, we went pony riding, accompanied by some parents. One of our campers’ fathers is very obese, and the ponies were small, meant to carry the weight of children or, at most, average-sized adults. Fortunately for the pony involved, Mr. Big decided to forgo the ride. But does halachah address whether he would have been permitted to ride one of the ponies?”


The topic of tzaar baalei chayim, the responsibility to alleviate, avoid and prevent the suffering of animals, is discussed fairly extensively by the halachic authorities. One early source, the Sefer Chassidim, discusses this mitzvah in regard to this week’s parshah — within the context of Bilaam striking his donkey.

All authorities agree that it is forbidden to cause animals to suffer unnecessarily, such as to strike an animal out of anger or frustration (Sefer Chassidim #666). If an animal that is normally well-behaved and responsive to its vocation refuses to work one day, one should not beat it to get it to cooperate – rather, one should consider the possibility that it might be ill (Sefer Chassidim #668). Animals do get sick and, as we see from the story of Bilaam, they may have difficulty expressing themselves. Thus, the Sefer Chassidim teaches that Bilaam was punished for striking his donkey (Sefer Chassidim #668). This esteemed early authority thereby implies that a gentile is required to observe the laws of tzaar baalei chayim, an aspect of the mitzvah that we will leave for a future article.

One should not work his pregnant animal too hard when he knows that it is ready to give birth (Sefer Chassidim #667). It goes without saying that it is prohibited to raise livestock in an inhumane way, such as by feeding them an unusual diet or depriving them of proper ventilation or exercise. Also, tzaar baalei chayim includes alleviating the suffering of an animal (Orach Meisharim Chapter 15:1).

Using animals

One may use an animal to service people, even though doing so involves inflicting pain on the animal (Nimukei Yosef, Bava Metzia 32b; Terumas Hadeshen 2:105; Rema, Even Ha’ezer 5:14; these authorities base their rulings on Talmudic sources, see Chagigah 14b; Shabbos 110b and 154b; Avodah Zarah 13b). The rationale provided is that animals and the rest of creation were created in order to service mankind (Terumas Hadeshen, based on Kiddushin 82a).

How much suffering?

A question raised by earlier authorities: Is there a limit to how much pain one may cause an animal, if the goal is for human benefit? We find a dispute among rishonim whether it is prohibited to burden an animal excessively, so that humans can benefit. For example, may I place a load on an animal that is greater than it should be carrying? According to the Sefer Chassidim #666, this constitutes tzaar baalei chayim. On the other hand, the Terumas Hadeshen (1:105) rules that this is permitted. He further discusses whether one may remove the down, which is the soft feathers, from live geese. Is this halachically the same as shearing sheep, which is certainly permitted, or is it prohibited because of the level of discomfort? The Terumas Hadeshen concludes that although any use of an animal is permitted and does not violate tzaar baalei chayim, the custom is not to remove the down from live birds because this is very painful. This conclusion is quoted by the Rema as standard halachah (Even Ha’ezer 5:14).

Scientific experimentation

Is it permitted to use animals to run tests for medical research or other scientific experimentation? The earliest discussion I found on this question dates back over three hundred years, in a responsum penned by Rav Yaakov Reisher (Shu”t Shevus Yaakov 3:71), who permitted it. A much lengthier and very thorough analysis of the topic is found in a more recent work, the twentieth-century responsum of the late rav of Zurich, Rav Yaakov Breisch (Shu”t Chelkas Yaakov, Choshen Mishpat #34). He concludes that one may use animals to test products to see if they are safe, although it seems that this is permitted only when there is a direct research benefit and the potential suffering of the animals cannot be avoided. In other words, it is permitted to test a new medicine or cosmetic item on an animal to see if medical problems develop, but one may only do this to the extent necessary to see if the product is safe. One may not, while experimenting, abuse the animals in any way that is not necessary for the test being performed.

What is the halachah if the medical testing will cause excessive pain to the animals? Is this still permitted? As mentioned above, all opinions forbid inflicting or causing any unnecessary pain to animals. Whether one may conduct medical test or research that will cause considerable pain to the animal might be the subject of a dispute between the Sefer Chassidim and the Terumas Hadeshen. The Terumas Hadeshen rules that this is permitted, as long as there is human benefit. The Sefer Chassidim states that even human benefit permits only a degree of normal discomfort to the animal, but not an excessive amount.

However, it is possible that the Sefer Chassidim agrees that one may test a medicine under these circumstances, since the importance of the potential benefit is great. It would seem that he would prohibit testing a new cosmetic item that will cause an animal to suffer tremendously, whereas the Terumas Hadeshen would permit it.

The Shevus Yaakov concludes that testing a medicine or cosmetic item on a living creature to see if it is safe for humans is permitted, even if it causes much suffering to the animal (Shu”t Shevus Yaakov 3:71). This is because one is not causing pain to the animal directly, and one is trying to research whether this product is safe for people.


Some authorities bring evidence from the story of Shimshon that, when necessary, one may even cause excruciating pain to an animal. The book of Shoftim tells us that Shimshon captured 300 foxes and tied together their tails in a way that each knot held a torch; he then sent the foxes into the fields and orchards of the Pelishtim, burning everything to the ground (Shoftim 15:4-5). Thus, we see that one can cause tremendous pain to animals when necessary for human need.

However, others question this proof, since during warfare, much is permitted that is not otherwise allowed. Thus, in general, causing this degree of pain to an animal would certainly be forbidden (Shu”t Chelkas Yaakov).

Furthermore, I question this proof, since nowhere does it say that the foxes themselves were on fire – the torches that they transported set fire to the fields and orchards of the Pelishtim.

Animals or even insects?

Does the prohibition of tzaar baalei chayim apply to all living creatures? We find a dispute among the acharonim concerning this issue.

Rav Moshe Feinstein (Shu”t Igros Moshe, Choshen Mishpat 2:47) discusses whether one is permitted to work as an exterminator of unwanted mice, insects and other such wildlife. He rules that this is permitted when it is necessary for people, but that one should try to avoid killing the unwanted creatures directly.

Rav Moshe’s reason is that although it is permitted to eliminate pests when they are harmful to mankind, killing them still remains an act of cruelty that makes an impression on the neshamah of the person who does it. Rav Moshe demonstrates this from the fact that after we fulfill the mitzvah of destroying the ir hanidachas, the city that goes wayward, the Torah promises that Hashem will provide rachamim to the Jewish people (Devorim 13:18). Rav Moshe quotes the Ohr Hachayim, who says that notwithstanding that this destruction is necessary and fulfills a mitzvah, it still affects the neshamah of those involved, because doing brutal things makes one into a nasty person. However, the Torah promises that Hashem will provide us with rachamim, meaning that He will restore us to being our usual, merciful selves. In other words, He will remove from our neshamos the harm created by what we were forced to do. (To the best of my knowledge, this is one of only three places in all of Rav Moshe’s responsa that he quotes the Ohr Hachayim.) Similarly, exterminating varmints, even though it is necessary and therefore permitted, will affect one’s neshamah. Therefore, it is better to do the exterminating in an indirect way, which makes less of an impression on the neshamah. According to Rav Moshe, we can conclude that killing a fly, moth or other insect that is not bothering anyone is prohibited.

(Rav Moshe contends that shechting for food will not cause a person to become cruel, since this act fulfills a mitzvah, notwithstanding that one is not required to perform it. Rav Moshe seems to hold that since the Torah sometimes requires shechitah, such as, when offering a korban, its performance could never cause someone to become cruel.)

Insects should not apply

However, we find that an earlier authority, Rav Yaakov Emden, who sometimes referred to himself by his acronym Ya’avetz* (Yaakov ben Tzvi), did not understand that the concept of tzaar baalei chayim extends this far. He rules that tzaar baalei chayim does not apply to insects, but only to creatures large enough that mankind can use them for work (She’eilas Ya’avetz 1:110). Although Rav Yaakov Emden quotes the Arizal as having commanded his students not to kill even lice, the Ya’avetz explains this to be a midas chassidus, beyond the strict requirements of the halachah. In his understanding, it could be that the Arizal prohibited this destruction because it causes harm to one’s neshamah, the same line of reasoning that Rav Moshe applied to discourage an exterminator from killing insects in a direct way.

Is it prohibited min hatorah?

The tanna’im dispute whether the law of tzaar baalei chayim is min hatorah or whether it is only of rabbinic origin (Bava Metzia 32b; Shabbos 154b). One of the differences that results from this dispute is as follows: Let us assume that in order to avoid causing an animal pain or distress, one would need to violate a rabbinic prohibition. May one supersede the rabbinic prohibition in order to avoid tzaar baalei chayim? The answer is that if tzaar baalei chayim, itself, is only a rabbinic prohibition, one cannot violate one rabbinic mitzvah for the sake of another. However, if tzaar baalei chayim is prohibited min hatorah, then preventing suffering to an animal overrides a rabbinic prohibition (Shu”t Maharam meiRottenberg 3:181).

The following discussion of the Gemara will demonstrate this to us:

Rabban Gamliel’s donkey was laden with barrels of honey, and he did not want to unburden it until Shabbos was over. The Gemara asks why Rabban Gamliel waited until Shabbos was over, since this was clearly causing unnecessary discomfort for the animal. The Gemara replies that the honey had hardened and was therefore no longer suitable as a food, which would make it muktzah on Shabbos. The Gemara then asks why didn’t Rabban Gamliel release the ropes binding the barrels to the donkey so that they could fall off the donkey on Shabbos, something he could do without moving the muktzah. The answer was that Rabban Gamliel did not want the barrels to break. The Gemara, still not satisfied, asks why didn’t he place pillows under the barrels, thus cushioning their fall so that they would not break? The Gemara answers that the pillows would get dirty this way and become useless for the rest of Shabbos, and doing this on Shabbos is prohibited because of a rabbinic proscription called bitul kli meiheichano, literally, nullifying a tool from its use. The Gemara then asks that the prohibition of tzaar baalei chayim should supersede the rabbinic prohibition of bitul kli meiheichano. To this the Gemara replies that Rabban Gamliel held that the law of tzaar baalei chayim is only rabbinic, and therefore it does not supersede a different rabbinic prohibition (Shabbos 154b).

The Gemara’s conclusion

Notwithstanding Rabban Gamliel’s position that tzaar baalei chayim is forbidden only as a rabbinic injunction, there are other tanna’im who rule that it is forbidden min hatorah. The following passage of Gemara implies that Rabban Gamliel’s position is rejected by the later authorities in the time of the Gemara:

Rav Yehudah said in the name of Rav: One may place cushions and pillows underneath an animal that fell into an irrigation ditch to enable it to get out by itself. However, it is preferred to bring food and water to the animal for the rest of Shabbos, if possible, and if this will satisfy the animal’s needs, rather than place cushions and pillows underneath the animal, which will violate bitul kli meiheichano (Shabbos 128b).

This Gemara implies that if we can avoid both transgressing the law of bitul kli meiheichano and avoiding tzaar baalei chayim, we strive to accomplish both, but if that option does not exist, then tzaar baalei chayim supersedes the rabbinic prohibition of bitul kli meiheichano. Since this passage reflects the conclusion of the amora’im, we see that we do not rule in accordance with Rabban Gamliel, but rather we rule that tzaar baalei chayim is min hatorah. This is the halachic conclusion reached by most, if not all, halachic authorities (Shu”t Maharam of Rottenberg 3:181; Mordechai, Shabbos #448; Nimukei Yosef, Bava Metzia 32b; Sefer Chassidim #666; Shiltei Hagiborim, Shabbos chapter 18, pg. 51a note 3, quoting Riaz; Kesef Mishneh, Hilchos Rotzeach 13:9; Rema, Choshen Mishpat 272:9; Sma 272:12, 15; Gra, Choshen Mishpat 272:11). This law is also codified in Shulchan Aruch (Orach Chayim 305:19).

The Shulchan Aruch, reflecting this conclusion, cites a different halachah that results from the fact that tzaar baalei chayim is prohibited min hatorah. Although there is a rabbinic injunction prohibiting mounting or dismounting from an animal on Shabbos or Yom Tov, if someone did mount an animal, he is required to get off. (If this were forbidden, he would be required to remain on horseback the rest of Shabbos or Yom Tov, which would certainly cause tzaar baalei chayim.) This is true, notwithstanding that the act of dismounting constitutes a rabbinic violation of Shabbos (Shulchan Aruch, Orach Chayim 305:18). This ruling is consistent with our previous analysis. Since we conclude that tzaar baalei chayim is prohibited min hatorah, it can, when necessary, supersede a rabbinic prohibition, such as that of dismounting from an animal on Shabbos.

Violent rooster

Here is a related question, culled from the more contemporary responsa literature. If one discovers on Shabbos that one rooster is attacking other chickens, may one remove it from the coop on Shabbos, notwithstanding that a live animal is muktzah on Shabbos (Shu”t Har Tzvi, Orach Chayim 1:205)?

This question was asked of the late Rav Tzvi Pesach Frank, then rav of Yerushalayim. In his analysis of the topic, he quotes the previously mentioned conclusions of the Shulchan Aruch, that someone who mounted an animal on Shabbos should dismount it, because of tzaar baalei chayim, and that one must remove a burden from an animal, even by moving muktzah if no other method will work, because of tzaar baalei chayim. Therefore, Rav Frank concludes that it is permitted to remove the treacherous rooster from the others. He writes that it is preferred to have a gentile worker remove it, but if there is no gentile available, a Jew may remove it, notwithstanding that a rooster is muktzah on Shabbos. In other words, tzaar baalei chayim supersedes the prohibition of muktzah, when there is no way to accommodate both laws.


Shlomoh Hamelech teaches (in Mishlei 12:10) Rachamei re’sha’im achzari, that the compassion of the evil is cruelty. What does this mean, particularly since the context of the pasuk implies that it is discussing the care one takes of his animals? The example chosen by the Sefer Chassidim (#669) is of an evil person who fed his animal well, but then expects it to perform beyond its capabilities – after all, he treated it so nicely. When the owner’s expectations are not realized, he beats the animal mercilessly. It turns out that his initial compassion caused him to be cruel.

The Tosefta (Bava Kama, end of Chapter 9) states that Rabbi Yehudah said in the name of Rabban Gamliel: “Know this sign well: as long as you act with mercy, Hashem will have mercy on you.” Sefer Chassidim #666 notes: If we are merciful to our animals, Hashem and others will be merciful to us.

*Note that several different scholars are referred to by this acronym.