Rolly pollies, also known as pill bugs or woodlice, are common invertebrates found in gardens and other damp environments. Despite frequent encounters, misconceptions exist about their nature and interactions with humans. This article clarifies their role in the environment and how they coexist with us.
The Truth About Rolly Pollies and Biting
Rolly pollies do not bite humans or animals. They lack the necessary mouthparts for biting, as their feeding structures are adapted for consuming decaying organic matter. These creatures are not aggressive and pose no threat to people or pets. They also do not sting or pinch. Concerns about them transmitting diseases are unfounded, as they do not carry or spread pathogens to humans.
Understanding Rolly Pollies
Despite common names like “pill bug” or “woodlouse,” rolly pollies are not insects. They are terrestrial crustaceans, more closely related to shrimp, crabs, and lobsters. Rolly pollies are the only crustaceans fully adapted to living entirely on land. They have an oval-shaped, segmented body, typically gray, measuring about one-quarter to five-eighths of an inch. They possess seven pairs of legs and two pairs of antennae.
These creatures breathe through gill-like structures, requiring moist environments to function. While needing moisture, they cannot survive submerged in water. When disturbed, their primary defense is to roll into a tight ball, known as conglobation. This behavior protects them and helps conserve moisture. Rolly pollies are often found in dark, damp places like under rocks, logs, leaves, and mulch.
Their Role in the Environment
Rolly pollies are detritivores, meaning they primarily feed on decaying organic matter. Their diet includes dead leaves, rotting wood, fungi, and other decomposing plant material. They also consume dead insects and, at times, decaying animal matter. By consuming this organic debris, they play a significant role in decomposition and nutrient cycling within ecosystems. They help break down decaying material, returning essential nutrients to the soil, which supports new plant growth.
Their activities can improve soil quality by processing organic matter and increasing its mineral content. Rolly pollies can even ingest heavy metals from the soil and crystallize them within their bodies, which helps to temporarily remove these substances from the environment. While they primarily eat dead matter, large populations may occasionally feed on tender young plants or seedlings, especially in very wet conditions.
Coexisting with Rolly Pollies
Encountering rolly pollies in or around your home is common, especially in damp areas. Since they are harmless and beneficial to the environment, the focus should be on managing their presence rather than complete elimination. Their appearance indoors typically indicates a moisture issue, as they seek out damp conditions to survive. They cannot survive for more than a few days indoors without a consistent source of moisture.
To discourage rolly pollies from entering your home, you can reduce moisture levels. This involves fixing leaky pipes or faucets and ensuring proper ventilation in basements, crawl spaces, and bathrooms. Sealing cracks and crevices around foundations, windows, and doors can also prevent entry. Removing outdoor harborage areas like piles of leaves, grass clippings, and excessive mulch close to the foundation can make your property less appealing to them. If found indoors, they can simply be picked up and placed back outside.