Henry (12 months, neutered) is a biter - he has bitten me a number of times since I brought him home a month ago, but usually it seemed it was in the context of play, like he was confused and though I was trying to play with him, and not really aggressive biting, and he had never broken the skin before. He does the same with the other cats, too. Well, last night I reached over to pat him, and he whirled around and bit my hand, hard, enough to break the skin and make it bleed. It didn't seem like play this time, either, he was swishing his tail. What do you do about biting? How do you teach a cat not to bite (is this possible, even)? Suggestions, please? Thanks very much!