Some say the rat will pee/poo in the cage, my answer is "why the hell are you feeding live rats to a snake to begin with?" You are playing Russian roulette and one day your snake will lose and you will either have a dead snake or one hell of a vet bill.
Not the thread for this topic, but you are giving ridiculously bad information here. It is perfectly fine to feed live prey to our pets (as long as you are a responsible keeper).