After trying most reasonable substrates, I've settled on aspen as being the best for both me and my snakes. Now that I have just woke my eastern hog from his long winter's sleep, I'm reconsidering the stratagy I used last season. Basically, this consisted of a pretty deep layer of aspen for my hog to tunnel in. Well, no doubt the snake appreciated this, he had tunnels all through it. Problem was, except for maybe an hour of basking in the early AM, the snake never showed himself. So I'm thinking this year I might go a little lighter on the depth just so I can see the snake more. What are your opinions?