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 onto 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 they are doing it. It's their nature. A dog is going to bark. A cat is going to vomit.