From what I read he's taking the rat pups now (or at least, he took one and ate it quickly). He should be fine eating those now every 4 or 5 days for a while. You don't want to feed him every other day for long periods, that is too often. Most people do 4 or 5 days up to 7 days. Your guy is hungry. Personally, I would just give him a rat pup every 4 days until he reaches 200g then switch him to 5 days for a while. This is all dependent on it being the correct size, of course.