You can never really understand Balls I've had some be on rats and refuse rats only to eat mice a few times and then go back to rats. I've had some eating f/t to refuse that and only want live. I've had some only eat in plastic tubs and others only eat in their enclosure. I've got an 09' Albino that eats like a pig as long as I hold his neck and touch his nose with the mouse he opens and I stick the head in and he bites and coils but leaving a dead mouse or rat, or live mouse or rat with him does nothing.

Throw him a live mouse I bet he'll eat it, then try a rat next time.