Sowbugs are common terrestrial crustaceans found in gardens and around homes. Though often mistaken for insects, they are distinct and play a unique role in their ecosystems.
Understanding the Sowbug
Sowbugs are terrestrial crustaceans, belonging to the order Isopoda, making them relatives of aquatic creatures like lobsters and shrimp. They measure between 0.25 to 0.75 inches long and have oval-shaped bodies with overlapping, hardened plates, giving them an armored appearance. Their bodies are somewhat flattened, and they possess seven pairs of legs and two pairs of antennae.
These creatures breathe using gills, a characteristic tying them to their aquatic ancestry. This means they require a consistently moist environment to survive, as their gills must remain damp for gas exchange. Without sufficient moisture, sowbugs can quickly dehydrate and perish.
Their World and Diet
Sowbugs thrive in habitats offering consistent moisture and darkness. They are frequently found under rocks, logs, leaf litter, and garden mulch, which protect them from drying out. They are primarily nocturnal, venturing out at night to feed.
Their diet mainly consists of decaying organic matter like dead leaves, rotting wood, and other plant debris. They function as decomposers, breaking down organic material and returning nutrients to the soil, benefiting the overall ecosystem. While they prefer decaying matter, they may occasionally feed on tender plant parts like seedlings or fruits that touch damp soil, especially if other food sources are scarce.
Sowbugs Versus Pillbugs
Sowbugs are often confused with pillbugs, commonly known as “roly-polies,” due to their similar appearance. A key difference lies in their defense mechanism: Pillbugs can roll themselves completely into a tight ball when disturbed, a behavior called conglobulation, which sowbugs cannot do.
Another distinguishing feature is at their posterior end. Sowbugs possess two prominent tail-like appendages, known as uropods, which protrude from their rear. Pillbugs, in contrast, either lack these visible appendages or have much less noticeable ones. Sowbugs also tend to have a flatter body shape compared to the more rounded or convex back of a pillbug.
Interacting with Humans
Sowbugs are generally harmless to humans, pets, and healthy plants. They do not bite or sting and are not known to transmit diseases. Their role as decomposers makes them beneficial in garden ecosystems.
When sowbugs are found indoors, it usually indicates they are seeking moisture, as the indoor environment is typically too dry for their long-term survival. They often enter homes through cracks, gaps around doors, or other openings at ground level. To discourage their entry, reduce moisture around the home’s foundation, seal entry points, and remove damp organic debris like leaf litter or mulch near the house.