I had a rat pup that my snake refused to eat once. I bought some soy based infant formula at the grocery store and fed it. I kept the rat pup alive long enough for my snake to eat it at his next scheduled feeding. The soy based infant formula was recommended by a website that I found online on how to care for orphaned rats. By no means should you freeze or whack the rat pup. That is just inhumane. You need to be prepared to deal with the fact that your snake may not always eat a meal and that you may be stuck with a live rat or mouse. Good Luck to you.