Do your leopard tortoises ever burrow, because I heard they were supposed to burrow all the time so the substrate is supposed to be deep but mine never burrows.
Leopard tortoises are not a burrowing species. The reason their shells are patterned like they are is so they become nearly invisible while hiding under bushes. The sun shining through the leaves makes the pattern of the leopard blend in with his surroundings.
The hatchlings I have had bury themsleves in the mulch so you can only see the top of the shell I think it must make them feel safe as they get bigger they stop doing it
They are actually not a burrowing species at all. Babies will sometimes squeeze into a small crevise or something in the substrate, but they don't dig holes (except to nest)