Pill bugs (Armadillidium vulgare)
Any species of terrestrial crustacean
in the genera Armadillidium
(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. Seealso sow bug
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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.