I would guess its temp related. I would shoot for 90 on hot side. Those stick on zilla thermometers aren't accurate. Go to Walmart and get an Accurite. It will measure your hot, cold, and humidity. Loads better than those stick on ones. Also, is your heat pad on a thermostat? That is a must! Otherwise it could easily get too hot and burn your snake. How big is your snake? If he's young or a hatchling, that tank is huge and could be part of your problem.

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