Long fiber sphagnum moss lasts a long time in vivariums or isopod breeding tubs, and has natural anti-fungal and anti-bacterial properties. It is placed between the substrate and leaf litter layers. It is best to keep the sphagnum moss off to one side of the enclosure to help maintain proper micro climates. This is to increase the suitable environment for microfauna. The moss substrate will need to be expanded in water previous to use. Isopods will slowly eat the moss overtime and will eventually need to be replaced after several months. Long fiber sphagnum moss is best to keep damp, but not worth extremely wet.