Any species of terrestrial crustacean in the genera Armadillidium and Armadillo (both in the order Isopoda), native to Europe and introduced worldwide. Pill bugs (sometimes called wood lice) resemble tiny armadillos in appearance and behaviour; they have a gray, oval body covered with platelike armour and, when disturbed, roll into a ball. They are about 0.75 in. (19 mm) long. Pill bugs live in dry, sunny places, in dry leaf litter, and on forest edges. See also sow bug.
Pill bugs (Armadillidium vulgare)—E.S. Ross
This entry comes from Encyclopædia Britannica Concise.
For the full entry on pill bug, visit Britannica.com.
Seen & Heard
What made you look up pill bug? Please tell us what you were reading, watching or discussing that led you here.