First thing to check is whether he’s ever been vaccinated for rabies. Even if it was only one time in his life, you should be safe from rabies as a reason for a bite. If he broke the skin and drew blood, there’s a good chance you can get an infection. Cat bites are notorious for causing serious infection. Dog bites tend to cause trauma more than anything but cat bites: infection. Once you’ve taken care of potential infection, then it’s time to consider medical or behavioral reasons why your cat maybe biting. Perhaps your cat has pain. If he is an older cat, this is highly possible. Over functioning thyroid gland (hyperthyroid) is another reason for a mood or behavior change that might cause the cat to bite. Or perhaps a bladder infection. There are many medical reasons to pursue if your cat has a change in behavior and is biting. Now, if your cat is young and perhaps you don’t know it’s history (or maybe you do know his history and he came from a shelter or rescue, perhaps he was weaned younger than normal), then your cat may not have learned bite inhibition. When kittens play rough with each other and/or their mother and they accidentally bite too hard, the kitten is punished by the other cats. The other cats may retaliate by biting back or by swatting. Some cats may cry, then go away from the situation. Losing a playmate is punishment in itself. Regardless, the cat who bites too hard learns not to do it again – bite inhibition. So if a cat is weaned at a young age, it may not learn not to bite too hard. Consequently, a cat who did not learn bite inhibition may bite his/her owners too hard. These kittens often respond well to another cat, so the two can play together and teach each other better behavior. Some cats have very strong prey drives – very strong desire to hunt – and if not kept busy with alternatives to hunting, they may “attack” their owners. Again, another cat may help with this behavior. Finally, some cats bite when they become overstimulated – a lot like a kid on candy and soda. So, just as a diet of healthy food calms the child, a diet of meat based canned cat food (or, even better, real food) will calm the kitty and decrease biting tendencies from overstimulation.