Roly-poly bugs are known for curling their tiny gray bodies into tight balls when touched or otherwise disturbed. Commonly known as pill bugs, sow bugs or woodlice, the roly-poly is a common garden guest, and while the appearance of these bugs may be disturbing to those who dislike all manner of creepy-crawlies, they do not bite or sting, nor do they cause any real harm to the surrounding environment.
Scientifically, roly-polys are known as Armadillidium vulgares, and while many people view them as members of the insect family, in reality they are not insects at all -- they are crustaceans. As such, they more closely related to shrimp and crayfish than they are to beetles and mealybugs. They are, in fact, the only land-dwelling members of the crustacean family. Roly-polys are blue-gray in color and approximately 1/4 to 1/2 inch long. The body of a roly-poly is covered with protective plates and bears two sets of antennae and 14 legs. In response to environmental stimuli, the tiny creature protects itself by rolling its body into a ball, which is how it earned the well-known “roly-poly” moniker.
Roly-polys favor damp, dark place and can often be found hiding under rocks, paving stones or fallen tree limbs. Should they make their way indoors, roly-polys tend to seek refuge in the moist, cool confines of basements, utility rooms or crawl spaces. Roly-polys have evolved to live on land, but they are not far removed from their water-dwelling cousins, and will perish if exposed to dry conditions for more than a few days time.
Role in the Garden
Roly-polys are decomposers. They feed on decaying organic materials, breaking down grass clippings, old leaves and other garden waste, and turning them into humus -- a dark, nutrient-rich substance that nourishes the nearby flora. When there is no moldering plant material to be found, roly-polys dine on the fresh leaves and soft fruits of garden plants. While they are not commonly thought of as pests, in large numbers they can damage young seedlings or ripening fruits.
Keep the population of roly-polys under control by reducing the amount of moisture in the garden. The roly-poly cannot tolerate waterless conditions and will actively avoid dry areas of the yard. Use inorganic mulches, such as gravel or shredded rubber, rather than natural mulches, such as wood bark or cocoa hulls, as these organic materials provide roly-polys with a long-term source of nutrition. Additionally, remove any pulled weeds, piles of rocks or other yard waste immediately as collections of refuse are sure to attract roly-polys and other unwanted pests.
- Kansas State University Research and Extension; Woodlice in the House? No Problem: Roly-Poly Poses No Threat Indoors; Kathleen Ward; June 2010
- University of Kentucky Department of Entomology; Sowbugs and Pillbugs; Michael F. Potter; April 1998
- University of Missouri Extension; Sowbugs, Pillbugs, Millipedes and Centipedes; Richard M. Houseman; August 2007