Animals

Woodlice

by Marcia Malory

Woodlice are crustaceans, like lobsters and crabs, but they live on land rather than in water.

They are isopods, a major group of aquatic and terrestrial crustaceans.

Woodlice live in dark, damp places in forests, for example, underneath damp logs, and venture out at night when it is cool and damp.

Unlike insects, woodlice do not have a waterproof coating (cuticle). To prevent moisture loss, woodlice instinctively rest in damp, dark, enclosed places. They move toward light, and they more move slowly as the humidity increases.

A woodlouse has seven pairs of legs attached to the main part of the body

Special limbs that are used in respiration can be found at the back end of its body. Males also use these limbs to transfer sperm to females during mating.

Woodlouse, photo by Andre KarwathDiet

Woodlice eat decaying matter, predominantly leaf litter - dead leaves that fall to the forest floor.

They also eat fungi and green algae that grow on tree trunks.

They play an important role in breaking down plant detritus (dead plant matter) and returning nutrients to the soil.

Woodlice can't absorb all the essential nutrients from their food the first time it passes through their gut. To solve this problem, they eat their own feces. The bacteria in the feces break down the food enough so that nutrients are released in the food's second trip through the digestive system.

Mating

During mating, the male woodlouse mounts the female. He uses his modified rear limbs to transfer his sperm to genital openings on the female's underside.

Once the eggs are fertilized, they are laid into a brood pouch that is filled with liquid. This pouch lies underneath the main part of the female's body.

After the eggs hatch, the young stay in the pouch until they are mature enough to resemble small adults.