I would just make sure to completely supervise the entire feeding process to make sure no mouse bites your snake. Make sure the mouth of the strangled mouse is always in your view, or it could be biting the inside of your snake's mouth. Try to get the snake to bite down on the mouse's neck or side, rather than onto its face, whereby the mouse could injure the insides of the snake's mouth. You should really "whack" the mice first; my picky eater who would "only" eat live mice when I got her, took readily to freshly-killed mice and now rat pups. I just move it around in front of her (using tongs) and she thinks it's live, and snap!