Details
Armadillidium vulgare
The common pill bug is a small land isopod and familiar decomposer. It feeds on dead plant matter and rolls into a tight ball when threatened.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It lives in Palearctic and Nearctic forests, grasslands, gardens, and urban plantings. Damp soil, stones, and leaf litter help it avoid drying out.
Length 0.8-1.8 cm; weight 0.05-0.2 g. The grey oval body is covered by hard plates, with short legs tucked underneath. When rolled up it forms a nearly seamless ball.
Nocturnal and loosely gregarious, it often gathers where moisture is high. It wanders in damp conditions and retreats under cover as surfaces dry.
A detritivore, it eats dead leaves, decaying plant fragments, and fungi. Its shredding helps break organic matter into soil.
Females carry eggs in a brood pouch beneath the body. Young emerge as small versions of adults and grow by molting in two stages.
It is listed as Least Concern and thrives around people. Despite its common name, it is a crustacean related to marine isopods, not an insect.
