Smulkin found some plastic pegboard at Lowe's which he original cut to fit the tops of our aquariums as an alternative to putting contact paper over screen tops. He later came up with the idea of cutting the pegboard to fit the bottom of the tank to provide a baffle between the substrate and the bottom of the tank. The snake might burrow down to the pegboard, but he won't get underneath that to the bottom of the tank. It works great!