I might look into those thanks for the suggestion. I think I've worked out why he does it and I don't know why I didn't see it before. He bashes his hands on things and things together and dances and sings to music and I noticed today when he tried to hit his head on the cupboard he was shaking his bum to the beat. I think it's the noise that intrigues him because he was slapping the tiles as well. He has enough toys that make noise why does he need to use his noggin as a drum!! Arg