I don't think mice are much problem. Rats are different story, as they have very sharp teeth. I mean sharp. Even the little guys. Like the others said, it mostly depends on how well the snake grabs the little bugger. I've watched in horror as a mouse was chomping away on the side of one of my snakes. Thought she'd be all tore up, but after checking her over 10 times after feeding, not even one scale was scratched. Gotta' remember that they take live prey exclusively in the wild. With that said, definitely try to get your snake to take dead prey because it is much safer for the snake. Try the stunned method to switch over if need be. Just take a spoon or something blunt and give a good whack on the mousey's head. Nine times outta' ten, they'll twitch and flop around for awhile. Usually long enough to get your snakes attention anyway.