Holding the snake by the head, I smack the bejesus out of it with the rat to make it angry enough to strike..then leave them to it in the gladiators arena, and let nature do the rest.
Seriously: I feed males and females alternately..not on the same day...so, open tub, drop in rat, move on to next tub. Give everyone 30 minutes..then make rounds to remove any uneaten prey.