Pillbugs, also known as roly-polies, are small, terrestrial crustaceans belonging to the order Isopoda. They are commonly found in moist environments, such as gardens and under rocks, where they feed on decaying plant material. Unlike insects, pillbugs have a segmented body and can roll into a ball when threatened, which is a unique defense mechanism. These creatures are often mistaken for insects but are more closely related to crabs and shrimp. Pillbugs breathe through gills, which is why they need a humid habitat to survive. They play an important role in the ecosystem by helping to decompose organic matter and enrich the soil.