Create a desert-like environment that is easy to maintain with Exo Terra Sand Mat Desert Terrarium Reptile Substrate. Substrate is necessary to the health and well-being of your pet because it absorbs waste, helps control humidity levels and encourages burrowing. The Exo Terra Sand Mat Desert Terrarium Reptile Substrate is a safe, hygienic substrate substitute that is sturdy, easily removable and easy to clean. Unlike loose sand or soil, the Exo Terra Sand Mat Desert Terrarium Reptile Substrate cannot be accidentally ingested.