Sowbugs & Pillbugs

Sowbug Facts

Sowbugs and pillbugs are not actually insects but crustaceans that are related to lobster, shrimp, and crayfish. They are one of the few organisms in their class that has adapted to living on land.

Various species of sowbugs and pillbugs can be found throughout the world. They are not harmful to people or cause structural damage. These critters are only considered pests when they slip inside your house looking for food or a damp place to hideout.

Sowbug Bites

Both sowbugs and pillbugs do not bite people. These little critters may occasionally enter your house and are just nuisance pests. They will not spread disease or cause structural damage to your home.

Sowbug Infestation

Sowbugs and pillbugs are primarily active at night and during the day they hide in cool, damp spaces. You can find these critters under stones, logs, or pretty much any object sitting on damp earth. They can also be found in compost heaps, mulch, and the space where the grass meets the foundation or sidewalk.

Sowbugs and pillbugs are scavengers. They primarily eat decaying plant matter and fungus. Sometimes these critters may munch on young plants.

The sowbug and pillbug life cycle is an incomplete metamorphosis. They hatch from eggs looking like tiny versions of the adults and shed their skins several times as they grow. Sowbugs lay an average of 24 eggs per brood and will have one to three broods during the summer. It takes about 20 weeks for sowbugs to reach adulthood and they usually live for two years. Pillbugs carry an egg sac on the underside of the body and have an average of 28 young per brood.

Adult Pillbugs can also live around two years, sometimes longer. Spiders, centipedes, and even small mammals are common predators for sowbugs and pillbugs. Some Sowbugs can emit a chemical with a nasty smell and taste to deter predators.

Types of Sowbugs

Sowbug Identification

Sowbugs and pillbugs range from 1⁄4 to 5⁄8 inch long and can vary in shade from dark to slate gray. They have oval bodies with a segmented, rounded back that looks like armor, and chewing mouthparts. These critters have seven pairs of legs and two pairs of antennae, but only one pair of antennae can be easily seen. Sowbugs have two visible tail appendages while pillbugs do not. Pillbugs are able to roll up into tight little balls for protection which has earned them the names “roly-polies” or “roly-poly bugs”. Sowbugs and pillbugs breathe through gills found on their undersides.

Sowbugs in the Home & the Apartment

Sowbugs will sometimes sneak into crawlspaces and basements. They will slip inside under doors, through any cracks in the foundation, and through the gaps in expansion joints. Once inside, sowbugs or pillbugs will usually only live for a few days unless they find an area with excess moisture. If you are regularly finding sowbugs indoors, it usually means there is a large population of these critters breeding somewhere nearby on the exterior of the home.