You could stun the prey before feeding but I've heard good and bad things on that. I personally just toss them in the rack. Normally they snatch the prey right up but if they don't I take the rat out within 20-30 min. Ive been getting my rats from a private breeder but... I usually get them a day or two before feed day. I have a couple cages set up for the feeders and give them a couple good meals so they are essentially "gutloaded" and not hungry. Now I am slowly converting to breeding them which is more work for me but I know what the rats have been eating and being kept. I like that better. Or you could try fresh killed. The Rats will be fresh and at perfect temp at that point and you may spend a few more min at feeding time, but no bites. Even though I feed live I have never had any serious injury to any of my snakes. You might get a little nip here or there but if you are vigilant you could easily stop that with a chopstick inbetween teeth. Since I feed live though I always watch, immediatly take out any rats that aren't eaten, and I've always got a bottle of betadyne in the medicine cabinet for any accidents.