Pillbug Pervasiveness

We had a very wet spring this year—rainfall for April and May was twice normal. An abundance of rain in early spring rapidly changes the surrounding hues from winter's browns and grays to countless shades of green. It's a wonderful experience to see the growing season get such a watery boost and watch the garden vegetables luxuriate and flourish. The plants get so happy!

A wet spring causes many shifts in the balance of the local ecosystem, as compared to a dry spring. With lots of rain plants get a good season's start and insects abound, as they find many blossoms to visit. We'll be paying the price later, I fear, when mosquitoes and gnats will also proliferate. One of the unusual population explosions we've noticed this spring is pillbugs. These little terrestrial crustaceans, also known as woodlice or roly-poly bugs1, are always found in dark, wet spots. (Other delightful names are armadillo bug, doodlebug, roll-up bug, and chuggypig.) Since the wet spots have recently been everywhere, so have the pillbugs. Turn over a damp log and the bottom will be coated with these little guys. Lift some soggy mulch and bunches of pillbugs will scatter.

Pillbugs are in the family Armadillidiidae. Doesn't that make sense? A pillbug is about a quarter inch long, with 11 armored body segments. When threatened they roll into a ball, causing the critter to resemble a round little pill. This process is also known as conglobulation. (Doesn't that word just roll playfully off the tongue?) Kids call it roly-polying. These bugs also conglobulate when their environment dries up, to conserve water.

Pillbugs are one of nature's important agents for decomposing rotting wood and other decaying organic materials. They have even been kept by some people as pets—most often used to keep cages for rodents clean, by eating feces, mold, and discarded food. With that kind of diet we don't worry much about them causing any real harm, unless a bunch of them get into the strawberry beds and snack on the berries (it's their one sweet-tooth exception).

Every year is a little different in its particular mix of flora and fauna. Sometimes it's easy to ascribe and abundance (or lack) of a given plant or critter to the weather, but sometimes it also can be a mystery. If I keep a sharp eye out, maybe next year I'll solve a few mysteries.