my friend gave me him when he was about 8 weeks old, he was too viscious for her at the time, when he came to me he was quite playful as a kitten should be. My kids have never had the inclination to terrorise him, so I dont know where this comes from, but he sometime suddenly jumps up their backs and bite them on the shoulder. He also will attack my arm for no reason at all whilst in the middle of an ear ruffling. He does play gently, and he sometimes plays with his mouth, even my 2 and 3 year old knows he is not playing when he jumps up to bite them. As I said there is no reason at all for the attacks.