No sand. Causes R.I. and they can ingest it. Reptibark is fine although it's hard to find the poo in it cuz it's dark. My corns are more active when it gets dark, but I guess it depends on your snake. I got a new viv for my amel yesterday (dropped the %$^# other one while cleaning) and she spent an hour checking it all out. My aztec rarely comes out except very late at night.