A: Animals that “chew the cud” are those that partially digest their food, and then regurgitate it from their first stomach (most have a four chambered stomach) and chew it. Animals that “chew the cud” (also called “ruminating” animals) are mentioned in (Lev 11:3-26) and (Deut 14:6-8).
These are divided into 2 categories: clean (allowed to be eaten by man) and unclean (forbidden as food). If an animal had a “cloven foot” (a hoof split into 2 distinct toes) AND “chewed its cud,” it could be eaten (Lev 11:3). If an animal “chewed its cud” but didn’t have a cloven hoof, it was forbidden to eat it (Lev 11:4-5). Examples given of these “unclean” animals are the camel (Lev 11:4), the rock hyrax (badger)(Lev 11:5), and the hare (rabbit)(Lev 11:6). (A pig is also called unclean in (Lev 11:7) even though it has a cloven hoof, because it does not “chew the cud.” Examples of clean animals (called “kosher” by Jews) would be: oxen, cows, sheep, goats, and deer. (Lev 11:26) carries out just how bad unclean animals were by saying that if a person even touched them, they would be unclean.
There is some controversy about these verses because the rabbit and rock hyrax do not technically “chew their cud” (regurgitate their food and rechew it). Some use these verses to demonstrate the fallibility of the Bible. The explanation given by those who know about these things (not me) is that to “chew the cud” simply meant at the time it was written in the Bible “to rechew food that had been previously digested” and not necessarily “to rechew regurgitated food.” Rabbits actually DO rechew their food, but apparently they swallow the food, poop it out and rechew it a second time directly from their anus (yeah… I know… Do you still want a rabbit for a pet?). This distinction between simply rechewing partially digested food and rechewing regurgitated partially digested food supposedly wasn’t made until the 1800’s.