Why won't my baby Ball Python eat? It's an EMERGENCY!!!?

I have had him a week and a day. and a couple days ago I tried to feed him in his cage on a paper towel. he wouldn't eat. today I tried putting a warm mouse the appropriate size in a small dark container. with holes in the lid. and but him in. and he won't eat... What do I do? his normal cage temp is the appropriate temperature. and he has a hid and water and everything. every couple days or so I see some of his feces on his substrate. so he isn't necissarily starving. but what is wrong with him? What do I do? (I'm using frozen/ thawed mice)