Rolly pollies, also known as pill bugs, woodlice, or isopods, are common inhabitants of gardens and damp environments. Despite their common name, these small, segmented creatures are terrestrial crustaceans, making them more closely related to shrimp and lobsters than to insects. They possess seven pairs of legs and a hard, gray exoskeleton. Understanding their diet is central to appreciating their beneficial role within the ecosystem.
The Main Course Decaying Matter
Rolly pollies are classified as detritivores, meaning their diet centers almost exclusively on dead organic material found on the forest floor or in the topsoil layer. This foundational diet consists largely of detritus, including fallen leaves, decomposing mulch, and soft, rotting wood. By consuming this decaying matter, they break down tough materials like cellulose, which speeds up the natural decomposition process.
Their digestive process returns trapped nutrients back into the earth. As they feed, they excrete waste rich in minerals such as nitrogen, phosphorus, and potassium, increasing the overall quality and fertility of the soil. Their feeding habits also help control certain harmful fungi, maintaining a healthy microbial environment.
Specific Food Preferences
While general detritus forms the bulk of their intake, rolly pollies actively seek out specific items that are soft, moist, or already decomposing. They prefer molds and fungi, often consuming the vegetative part that grows beneath the surface. This scavenging behavior extends to soft fruits that have fallen to the ground, such as melon rinds, berries, and apples, especially once the outer skin is compromised.
These crustaceans also consume soft vegetable scraps and the tender parts of dead or dying plants, including tubers and roots. Their diet is not strictly vegetarian; they occasionally feed on animal matter, including dead insects and other decomposing animal flesh found in the soil.
Interaction With Living Plants
Rolly pollies generally prefer dead material and are not typically considered major garden pests. However, under certain environmental conditions, such as dense population or a lack of sufficient decaying matter, their diet can shift to include living plant material. They are most likely to target vulnerable parts of a plant, such as soft, newly emerged seedlings or tender, thin roots.
They may also damage fruits or vegetables resting directly on the soil, like strawberries, by nibbling holes in the moist underside. The damage they cause is often minor and limited to very young plants, which can sometimes be mistaken for the work of slugs or other pests.