Not like this point hasn't been made many times aleady...
buuuut....
Feeder animals (rats OR mice) can and do bite snakes. They dont bite them every single time, by all it takes is one time to cause some damage. i do a lot of rescue work and have seen, first hand - the damage that feeder rodents can cause.
I remember a young ball python i got a few years back, it had been fed a feeder MOUSE and had not killed it when he struck it, the mouse lived for awhile while the snake squeezed it and during this time it chewed the snake down to its spine.
This snake survived, but it was a long, grueing, painful rehab - and he was scarred for life.
Another good example is right here on this forum, check out the thread:
http://www.cornsnakes.com/forums/showthread.php?t=75746
this keeper has a corn who has been eating live for 7years with no issue, and this time the snake got bit right above him eye. Lucky he didnt loose the eye.
F/t is a more humane, safer, cheaper and cleaner (no parasites, disease etc) way to feed your cornsnake.
If you choose to feed live and take those risks, that is your own personal choice - but please do not make outrageous and false claims such as "feeder mice do not bite snakes." This is not even a matter of opinion, it is an outright, false statement.