I do not know what the cat can have eaten. Usually I know exactly what the cat has eaten. Not only have I fed it to the cat, at the cat's insistence, but the cat has thrown it up on the rug, and someone has tracked it all over on to the other rug. I do not know why cats are such habitual vomiters. They do not seem to enjoy it, judging by the sounds they make while doing it. It's their nature. A dog is going to bark. A cat is going to vomit.