Woodlice

Joseph Berger

Woodlice

Gary Alpert, Harvard University

Woodlice

General Description
Also known as “isopods,” these creatures are not insects but crustaceans more closely related to shrimp, crabs and lobsters. Most isopods are gray to brown in color and about one-fourth of an inch long with seven pairs of legs.

Pillbugs can roll into a ball when disturbed. Sowbugs have two tail-like appendages that form a tube to suck up water and are unable to roll into a ball when disturbed. Like many occasional invaders, isopods need lots of moisture. They live in damp places - under rocks, logs, leaves and mulch - where they feed mostly on rotting plant matter. Moisture-seeking pillbugs and sowbugs invade structures but do no damage indoors.


General Control
To prevent infestation, seal cracks in the structure’s foundation, install door brushes to fill gaps beneath doors, and correct moisture problems. As much as is practical, reduce moisture and vegetation around the foundation.