Some people have successfully fed their snakes live mice and never had a problem. BUT... and it's a big 'but', live mice generally want to keep living and will fight back if they can. At some point, your snake might end up on the losing end of a skirmish. Then you'd have to deal with a wounded snake, one who might not want to eat mice after that at all. Is it worth the risk? It isn't to me. I just used cervical dislocation on 10 mice yesterday and it went well. You have to just keep it in mind that these mice are food, and that what you're doing will cause it the least discomfort as possible, and eliminates several risk elements.