ALso, a rat pup is WAY too small. That's what I start hatchlings on. They rat should be as big around as the biggest part of your snake. And NEVER leave a live rat unattended with your snake. I agree with the post above....get a heat mat for under the cage and get your temps/husbandry right. A heat rock is only good for one thing......cut the cord off and use it as a paperweight. Seriously your snake can burn himself alive on a heat rock.