|Wood louse, also called sow
bug, is a small invertebrate (animal without a backbone) that lives on land. It belongs to
a group of mostly marine animals known as isopods. Like its marine relatives, a wood louse
has a flat, oval body that is divided into a number of segments. Special muscles enable
the animal to roll up into a ball when disturbed.
Most wood lice live in dark, damp, humid places, such as under stones and in bark. They
come out only at night to feed. A few species live in the desert. They burrow deep into
the sand to avoid daytime heat.
Scientific classification. The wood louse belongs to the subphylum Crustacea and the order
Isopoda. The most common species are in the genera Oniscus and Porcellio.
Contributor: P. A. McLaughlin, Ph.D., Research Scientist, Shannon Point Marine
Center, Western Washington Univ.