Check out Zoo Meds new Excavatorâ„¢ Clay Burrowing Substrate. It allows reptiles to dig tunnels and burrows just like they do in nature. Watch your reptiles perform natural digging behaviors; mold and create multi-level terraces and burrows in your reptiles terrarium Make your reptiles feel like they are at home" in their natural habitat. Excavatorâ„¢ holds its shape so burrows and tunnels wont collapse All Natural. No added dyes colors or chemicals."