Sowbug

These land-dwelling crustaceans are arthropods but not insects. They are worldwide in distribution. In the United States, the two most common species are Porcellio Laevis Kock and P. Scaber, both in the family Porcellionidae and of worldwide distribution.

Recognition

Adults are up to about 5/8 inch long, convex above but flat or hollow beneath. Color dark to slate gray. Typical of crustaceans, sowbugs with seven pairs of similar legs; two pairs of antennae, one tiny, the other readily visible; body dorsoventrally flattened, with 2 prominent taillike appendages which project out from body on posterior or rear end. Capable of rolling up into only a very loose ball when distributed.

Habits

Because water loss is such a problem, sowbugs are inactive during the day and remain hidden under objects to reduce moisture loss. During the day, they can be found around buildings in such places as under trash, boards, rocks, flower pots, piles of grass clippings, flower-bed mulches, and other decaying vegetation.

They occasionally enter buildings via door thresholds, especially homes with sliding glass doors on the ground level. Indoor invasion typically means that there is a large population immediately outside the building. Usually they do not survive indoors for more than a couple of days unless there are moist conditions and a supply of food present.