Zoo Med Premium Repti Bark Natural Fir Reptile Bedding is all natural and made from the bark of fir trees. It’s the perfect substrate for humidity-loving reptiles like green iguanas due to its ability to absorb moisture and then release it into the terrarium. In addition, the smaller chips provide better moisture retention while preventing live food from hiding in your substrate. Naturally decorative Repti Bark provides your terrarium with a tropical rainforest look.