They're snakes. They do what they want lol. As long as you offer the same kind of hides on the hot and cool side, then the snake will go to what it needs. One of my boas almost never goes to the hot side no matter what temp you make it. I just gave up and set it the same as the other boas and let her do her thing. I do catch her over there once in a great while though but its like the second coming of the messiah if you see it lol.