The fact that he always ate his dead mouse or rat before this shows that he is not averse to the idea. It seems like he may not need the quantity of food you are supplying him with. I would recommend waiting 7 days before you feed him again and see what his reaction is. You may be able to gauge what the best length of period between meals is by his reaction to the food. At least you know that if he is hungry he will eat the dead mouse, even if its not much of a challenge!