Shomrim of produce may eat by virtue of common custom, but not by virtue of Biblical law.  There are four [types of] shomrim: an unpaid shomer, a borrower, a paid shomer, and a renter. An unpaid shomer swears for everything; a borrower pays for everything. A paid shomer and a renter swear concerning an animal that broke a limb, an animal that was captured, and an animal that died, and they pay for loss and theft.

One wolf is not an unavoidable accident; two wolves is an unavoidable accident. R’ Yehudah says: At a time when wolves are sent out, even one wolf is an unavoidable accident. Two dogs is not an unavoidable accident. Yaddua the Babylonian says in the name of R’ Meir: From one direction, it is not an unavoidable accident; from two directions, it is an unavoidable accident. A brigand is an unavoidable accident. A lion, a bear, a leopard, a bardelas, or a snake is an unavoidable accident. When? When they came of themselves. But if he led them to a place [frequented by] bands of beasts or brigands, it is not an unavoidable accident.

[If] it died naturally, it is an unavoidable accident; [if] he afflicted it, and it died, it is not an unavoidable accident.  [If] it ascended steep mountaintops and fell, it is an unavoidable accident; [if] he took it up to steep mountaintops, and it fell and died, it is not an unavoidable accident.  An unpaid shomer may stipulate to be exempt from an oath; a borrower, to be exempt from paying; [and] a paid shomer and a renter, to be exempt from an oath or from paying.

[If] anyone stipulates contrary to Biblical law, his stipulation is void. Any stipulation which is preceded by the action —- his stipulation is void. Anything that is possible to fulfill at the end, and he stipulated concerning it in the beginning —- his stipulation is valid.