One who borrows a cow or any other thing from another and subsequently the cow dies or the item breaks while in the borrower’s possession, the value of the animal or item must be paid to the owner. The sages ruled that if the animal died or the item broke while being used properly, during commission of the work for which it was borrowed, the borrower is exempt from liability, for the work was the whole reason for the loan.
There was an incident in which a person borrowed a cat to rid his house and yard of mice. The mice united and killed the cat. Rav Ashi deliberated on this incident to determine whether the cat died in the pursuit of its work. What are the issues under debate? On one hand, the cat did die while doing its work, which is the killing of mice. On the other hand, mice do not customarily kill cats, and so this might be an extraordinary death for which the borrower might have to pay, as we wrote above. A different sage stated that there is no doubt about the matter and that there is no need for discussion. The cat died in pursuit of her work and the borrower is exempt, just as a man who had intercourse with many women and died as a result of the many acts of intercourse is considered to have died in pursuit of his work.

(Since the Talmud, before it was written down and edited, was an oral study by scholars, many times there are differing versions of incidents related, either due to forgetfulness or misunderstanding. Another version of a discussion is prefaced with the words “Some say:” or “Another version:”, as in the case of this issue.)

Some say that the incident was of a man borrowing a cat, and the cat eating many mice and dying. Rav Ashi deliberated on this incident to determine whether the cat died in the pursuit of its work. What are the issues under debate? On one hand, the cat did die while doing its work, which is the killing and eating of mice, so the cat died while working and the borrower should be exempt. On the other hand, eating mice does not customarily kill cats, and so this might be an extraordinary death for which the borrower might have to pay. A different sage stated that there is no doubt about the matter and that there is no need for discussion. The cat died in pursuit of her work and the borrower is exempt, just as a man who had intercourse with many women and died as a result of the many acts of intercourse is considered to have died in pursuit of his work.
(Babylonian Talmud, Tractate Bava Metzia 97a)