let him eat at his own pace by droping the foods on the ground force feeding him when hes not hungry gives you nothing and anything can completely fill up his stomach so dont let them eat seeds hell meander over towards any food item on the ground but be warned birch nuts and seeds gives him indegestion so he wont drop any fluff if you give him birchnuts and the like however he loves fleshy mushrooms and berries even petals will do