My car Percy is 5 years old and 2 years ago I adopted a kitten. Obviously he was a bit upset by this and would hiss and growl and sometimes even he would do it to me and the kids. He did this on and off for over a year until I moved. Then he just stopped and was playing happily with the other cat and they were best friends. The last week or so he's started doing it again though. He'll growl and swipe at the other cat. He doesn't do it if the other cat isn't in the room. Could he just be a grumpy cat? Or do you think something could be wrong? He's eating ok and doesn't look sick. It's just confused me because he stopped doing it for almost a year. Even now after a little while I spot them sitting together and he cleans the younger cat which I understand to be a sign of affection. So why he is growling and clawing sometimes and then sometimes he's ok?