Oniscid

Oniscid refers to a group of crustaceans belonging to the infraorder Oniscidea. These terrestrial isopods are commonly known as roly-polies, woodlice, or pill bugs. They are characterized by their segmented bodies, usually with seven pairs of legs. Oniscids are detritivores, meaning they feed on decaying organic matter, playing an important role in decomposition and nutrient cycling in their ecosystems.

These creatures are found in a wide variety of habitats, from damp forests and gardens to more arid environments where they seek shelter in humid microclimates. They possess specialized respiratory structures called pleopodal lungs, which allow them to breathe air. Their ability to roll into a ball, particularly in the case of pill bugs, is a defense mechanism to protect their soft undersides from predators.

Oniscids are oviparous, with females carrying their eggs and developing young in a ventral pouch. They are a diverse group, with thousands of described species distributed globally. While some species are considered beneficial for their role in waste decomposition, others can sometimes become pests in agricultural settings or indoor environments, though this is less common. Their study is part of the field of carcinology, the branch of zoology concerned with crustaceans.