IMO you people are arguing over nothing!!!...LOL....think about what you are saying!! If your snake is in your tub, and you shoot a tempgun at your snakes stomach....temp reads, lets say, hmmm 91 degrees....what matters if it was heated to 91 degrees by belly heat or by back heat? THE TEMP IS STILL 91 DEGREES!! What I am getting at is that according to the setup you have, back heat is just as effective, just as efficient, as belly heat. I dont think belly heat helps with digestion (IMO) any differently that back heat helps with digestion. 91 degrees is 91 degrees NO MATTER what direction it comes from!! Its like this...which is heavier a ton of feathers or a ton of bricks?? NEITHER...its still a ton!!