I once had a BCI attempt to eat a mouse butt-first. I thought, "hey, he'll get it down..." and left to go to a movie. Boy was I wrong. I came back three hours later and the mouse was still sticking out of his mouth (the elbows were caught on either side of his jaws.) The snake was lying half in his water bowl, on his back!

I flipped out thinking I had killed the snake. I picked him up and he threw up the (very slippery with saliva) mouse. It took 4 hours for his jaws to go back to normal.

I guess my point is, if they try to take the mouse butt-first, stick around to make sure they get it down.