I have two of those caves for my ball python but I dont use the moss stuff anymore. I tried the free sample that came with the caves but it would mold really quick. Probably cause i was getting it too damp but now I just use papertowels. Much easier to clean and the moss had a tendency to smell kinda bad. I just replace the papertowels twice a week. Run them under hot water and squeeze the excess water out and stick them in the caves.