He started doing this, or at least I started noticing him doing this, about 10 days ago. At first I thought he just had to scratch but as I kept watching him he will do it several times. I have looked at his teeth and they look normal. Compared to the other side of his mouth I can't see a difference. I haven't changed his diet or anything. There isn't anything lodged in there. Anybody have any clues as to why he may be doing this? Should I take him to a vet?