Hamster are notorious for doing that. One thing you can do is not put more food in the bowl until at least some of the "not so yummy ones" are gone.You can also take some of the sunflower seeds, (not all of them), out of his bowl before you give it to him. I really can't blame the hammies for doing that. After all, I'd pick Hagaan Daaz ice cream over my dinner anytime.