Cats bite for a range of reasons, including aggression. If your cat bites when you’re petting them, they might be saying they don’t like physical contact. Or they might be telling you that it’s not the right time, like if they’re resting, sleeping or eating. Or, in extreme cases, biting is a way for cats to let you know that they’re in charge. Cats use biting as a communication tool or a way of demanding attention.
Another reason for adult cats biting is that they might not have been handled a lot when they were a kitten. Gentle, loving exposure to humans helps kittens develop into friendly, well-mannered adults. If they’re not handled enough as kittens, adult cats can become aggressive towards humans when they try to pet or pick them up.
Finally, cats, especially kittens, can bite when they’re playing. Cats have a lot of natural, instinctive, predatory behaviour like stalking, pouncing, chasing, play fighting and yep, biting.