Let it sit for 4 hours,[varies on the size of the rat], then put it in a ziplock baggie, throw it in a cup of hot tap water for 10 minutes, take out, put in front of heat lamp to warm up the head for about a minute, and the snakes usually WHAM! go right for it. And for some, the stinkier the better. Havent had a nasty bleeder yet. Some do bleed when they get squeezed, but nothing traumatic. ^.^