Play aggression in cats, is another common problem, especially in adolescent kittens, so when a kitten is four months old, to a year old. It can really be a problem, because they have lots of energy, and they love to play, and if you had the kitten when it was very young, one of the things people like to do, is they like to play with their hands with kittens, and have the kitten grab onto their hands, either with it's claws or it's teeth. That sets you up for play aggression in the future, so one of the things you want to do if you have a cat, who is too rough when he's playing, is to separate yourself from the play, so don't use your hands directly. Use a little springy toy, like this little bouncing toy, so the cat can play using it's teeth and it's claws with this, and your hands and body are safely away. Another toy to do that with, is this over the door toy,so this hooks on the doorway, and there's a long elastic string, that your cat can bat this, and grab it, and play around with it, without harming you.