first the animal has got to feel secure. if there's alot of lights, or low humidity, or maybe an enclosure that leaves him feeling exposed, even alot of activity in the room the enclosure is in alot of snakes will get stressed out and not eat, or be picky eaters. Getting em to eat frozen thawed is not hard though, just have to make sure the food item is plenty warm enough especially at the head, make sure you have long hemostats or feeding tongs to offer the food item with so he doesn't pick up the heat signature from your hand instead of the rats, and just kinda gently wiggle it in front of him. If they sense the heat of a body that's the right size, smell food, see food moving about, and there's nothing causing the animal any stress, they generally eat.
