My snake (no, wait, my little boy's snake) changed behavior when I changed the substrate. The original was some kind of wood chips. I switched to shop towels (heavy paper towels). I made sure to put a couple of extra layers of shop towels on the area over the UTH. Ever since, Slithery (name chosen by my son) never goes into his warm side hide. When we get him out to play after he's been haning in the cool side hide, he feels cool to the touch. Temps in the tank are fine. I am not sure what to do about this (if anything). Any suggestions would be much appreciated.