Check out Zoo Meds new Excavator 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. Excavator holds its shape so burrows and tunnels won't collapse. All Natural! No added dyes, colors, or chemicals.