We have kept them in a pile of sand. Six inches is good. Using a self ballasted mercury vapor bulb we heat the sand surface to 110 or so. We put a one inch glass divider in the bottom below the sand and put water directly into the sand on one side of the tank divider only. The other hot end is dry. The lizard will visit the damp sand when thirsty and actually drink from between the grains of sand.
The source that references riverbeds 'AND' deserts likely should have said riverbeds 'IN' deserts!
Insects on the surface are eaten. Crickets work and also soft bodies grubs. Calcium is required.
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AMAZON REPTILE CENTER
