I have my two baby sulcatas in a 55gallon tank with a screen lid covered in tinfoil, with holes cut for the heat lamps, to help hold in heat. But it doesn't do much to hold in humidity. I have coco coir as substrate. I have to re wet the sort numerous times a day to keep any of the top layer damp. The bottom seems to stay fairly wet as I can always see condensation on the bottom, but the top drys out very quick and I have not seen either of mine try to burrow. Im thinking of getting a fogger meant for reptiles. Have also been thinking of just trying to make a new solid lid. Here is a pic of there set up. The front right corner is a buried log, the hide behind that is half a flower pot, it's also got moss inside and this is the only hide they use. The front left is their water bowl, and te back is supposed to be their damp hide with soil and moss. But have never seen them use it. Thanks for any help