The substrate (bedding) should be a natural material conducive to promoting humidity such as coconut husk bricks commonly found in pet stores. Some reptile enthusiasts use carpeting made specifically for terrariums. Another option is green moss, also available at pet stores. Regardless, follow the instructions for replacement and/or cleaning of the substrate to maintain the lizard's health and to minimize the contact with its own feces. Never use dirt, sand, or gravel because the lizard can ingest it during feeding, and its intestines may become impacted.