Woodlice are small, terrestrial crustaceans belonging to the order Isopoda. They are commonly found in damp environments, such as under rocks, logs, or leaf litter. Woodlice have a segmented body covered with a hard exoskeleton, and they breathe through gills, which is why they need moist habitats to survive. These creatures are often mistaken for insects, but they are more closely related to crabs and shrimp. Woodlice play an important role in the ecosystem by breaking down organic matter, contributing to soil health. They are typically gray or brown and can range in size from 5 to 18 millimeters.