build a reward system around it. Good luck
Coat his hips with some really nasty tasting balm. No reward. No punishment.
thankyou both.to be honest I don't even think he knows hes done/doing it he gets so angry! :-( it's not until hes calm again and notices the blood that he reacts to it.its the inside of his lid that hes biting so I can't think of a way to stop it other than putting my own finger in his mouth.