Roly-polies, also known as pill bugs or woodlice, are common invaders of homes, causing concern for many homeowners. These small, oval-shaped creatures are not insects but are actually terrestrial crustaceans, making them more closely related to shrimp and lobsters than typical garden pests. They are generally harmless decomposers that feed on decaying organic matter, but their presence inside a home is usually a sign of an underlying moisture issue. While they do not bite or spread disease, their sudden appearance indoors validates the need for effective control measures.
Identifying the Conditions Attracting Roly-Polies
Roly-polies are heavily reliant on high moisture and humidity to survive, as they breathe through gills that must remain wet to function. They lose water easily through their thin outer covering, which restricts them to damp, dark environments. Outdoors, their preferred habitats are shaded areas with abundant decaying organic matter, such as under logs, rocks, leaf piles, and dense mulch.
Any condition that creates a consistently wet microclimate near the home’s foundation will attract and sustain large populations of these crustaceans. This includes excessive landscape watering, poor soil drainage, and large accumulations of grass clippings or leaf litter. When outdoor conditions become too dry or overpopulated, or when the weather changes, they seek refuge indoors, usually entering through low-level points.
Common entry points into a structure are any gaps or cracks in the foundation, unsealed door thresholds, and improperly sealed window frames, especially at ground level. Once inside, they gravitate toward damp areas like crawl spaces, basements, laundry rooms, and under-sink cabinets, where a hidden leak or high humidity offers a temporary chance of survival. Indoors, they typically cannot survive for more than a few days without the sustained moisture they require, meaning their indoor presence signals a larger moisture problem.
Immediate Non-Chemical Control Methods
For immediate reduction of the indoor population, manual removal is the quickest and safest non-chemical method. Roly-polies found inside can be easily swept up with a broom and dustpan or removed with a vacuum cleaner, after which they can be released outdoors far from the house. This is effective because they do not move quickly and do not pose a danger to humans or pets.
A simple and effective trapping method involves using their need for moisture and decaying food against them. You can create a temporary lure by placing hollowed-out potato halves, citrus rinds, or damp, rolled-up newspaper in areas where they congregate. The crustaceans will be attracted to the dark, moist shelter and can be collected and disposed of the following morning.
The most impactful immediate action is to rapidly dry out the affected indoor areas. Using a dehumidifier in a damp basement or crawl space will reduce the ambient humidity below the threshold required for their survival. Removing all damp debris, such as wet cardboard boxes or old papers, eliminates both a food source and a hiding spot.
Long-Term Exclusion and Structural Barriers
Achieving long-term control focuses on eliminating the outdoor conditions that support large populations and blocking their entry into the home. Start by creating a dry, vegetation-free buffer zone, at least 12 inches wide, around the entire perimeter of the foundation. This involves removing dense mulch, leaf litter, and excessive plant growth immediately adjacent to the structure.
Managing exterior moisture is important, as water pooling near the foundation is a major attractant. Ensure that all gutters and downspouts are functioning correctly and that downspout extensions divert water several feet away from the house. Checking the exterior grading to confirm that the soil slopes away from the foundation will prevent rainwater from collecting against the walls.
Sealing potential entry points is a structural solution that prevents future invasions. Inspect the entire foundation, sealing any cracks, crevices, or gaps with a suitable caulk or sealant. Pay close attention to utility penetrations, where pipes, wires, or vents enter the home, as these often have small, unsealed openings.
Modifying the landscaping can discourage future infestations. Consider replacing heavy, moisture-retaining organic mulch with drier materials like gravel, lava rock, or coarse sand in the buffer zone near the house. Adjusting irrigation schedules to water early in the day allows the soil surface to dry before the roly-polies become active at night.