Many basic arguments regarding bor are brought. One is not responsible if a person falls into the pit and dies (but one is responsible for damages). One is not responsible for vessels that fall in but Rabbi Yehuda disagrees and says one is responsible. The verse mentions just animals – an ox and a donkey. Drashot are brought to explain from where do we know that all animals are included (even birds). The mishna explained that one is obligated for an ox that is deaf, dumb or young. That seemed to imply not if the animal was older and not blemished. the rabbis at first think that somehow the mishna also includes that case but eventually concludes that one is not responsible for that case as an ox should also be paying attention (like a person) and therefore the owner is not responsible. There is an argument between the Rambam and Raavad about whether this is only true for death and not damages (as by a person). The mishna then brings other cases in the Torah where specific animals are mentioned and yet the intent is all animals. The gemara explains the derivation in each case.