I have a 1300g BP that won't eat rats. Tried scenting, even tried rubbing the mouse smell on the rat. Somehow he just knows it's a rat and won't eat it.
I then offer him a mouse and he gulps them down 5-6 a week. Go figure. Wish he'd go to rats since it'd be cheaper and less time consuming, but not much I can do about it if he just won't eat them!