Pillbug / Sowbug
Pillbugs and sowbugs are dark gray, ¼- to 5/8-inch long, oval crustaceans that are humpbacked, appear to be covered with segmented armor, and have seven pairs of similar legs. Pillbugs can be distinguished from sowbugs because pillbugs are able to roll up into a ball when alarmed and lack the two prominent tail-like appendages that characterize sowbugs.
Female pillbugs and sowbugs carry their eggs in a “brood pouch” or marsupium where the young hatch in about 45 days. There are 24-28 eggs in each brood and one to three broods produced each year. They young molt every one to two weeks until they become adults. Adults live about two years.
Pillbugs and sowbugs usually are found in moist situations where they feed on organic matter. They are commonly found outdoors under stones, boards, and piles of plant material. Pillbugs and sowbugs invade basements, crawlspaces and sometimes other parts of structures that have higher-than-normal moisture. They cause no damage but are considered a nuisance. Unless disturbed, they are usually active only at night.