Today my cat started laying his ears back flat, looking very annoyed, scratching his left ear very often, and shaking his head a lot. I thought he'd gotten something in his ear. I took him him to the vet, who looked in both ears. He said his ears are beautiful, no mites, dirt, infection, nothing at all. He looked all the way to the eardrum and saw nothing. He didn't suggest anything else it could be. But my poor kitty still seems to be very miserable with his ear, scratching at the left one and laying it back. I have no idea how to help relieve his discomfort, except for a good ear rub, which just makes him shake his head. Suggestions?