Roly-polies, also known as pill bugs or woodlice, are small, terrestrial crustaceans belonging to the order Isopoda. They are easily recognized by their rounded, segmented bodies and can roll into a ball when threatened. Roly-polies are typically found in moist environments, such as under rocks, logs, or leaf litter, where they feed on decaying plant material. Unlike insects, roly-polies have seven pairs of legs and breathe through gills, which is why they need a damp habitat. They play an important role in the ecosystem by helping to decompose organic matter, enriching the soil as they break down dead plants and other materials.