I have been having issues with my cat for a while. He has been biting me almost every night now. Sometimes even during the day. I don't know what I have done to trigger it. One second I have him in my arms, petting him and he is purring like a motor boat. When o go to put him down on my bed or either on the floor and I walk to go get something, he follows me and suddenly attacks my leg. He has bitten me many times already and this has always been the case when he bites. I've never given him shots before but hasn't been showing symptoms of rabid behavior. Could someone please explain to me what's going on with my cat and if I should be worried?