Thanks for the input, I guess I just don't understand why the probe would go in between the uth and the glass on the bottom other than if the snake burrows down so it wont burn him. Even if I place the probe between the uth and glass I will have to set it to a higher degree to get the substrate warm enough. I guess I can always make the substrate less thick under his warm hide. Sorry to be a pain, I just trying to understand all this.