Woodlice are commonly encountered in and around homes. This article provides insights into their biology, natural behaviors, and practical approaches for managing their presence in residential settings.
Understanding Woodlice
Woodlice are terrestrial crustaceans belonging to the suborder Oniscidea, making them more closely related to crabs and lobsters than to insects. They are often recognized by various common names such as pill bugs, roly-polies, sowbugs, or slaters, reflecting their appearance or behavior. These creatures possess a segmented, dorso-ventrally flattened body, typically grey or brownish in color, with seven pairs of jointed legs. Their size generally ranges from approximately 2.5 millimeters to 18 millimeters in length.
A distinctive feature of woodlice is their hard, armor-like exoskeleton, which they shed in two stages as they grow, starting with the back half. Some species, particularly those in the family Armadillidiidae, can roll completely into a tight ball when disturbed or to conserve moisture, earning them the “pill bug” moniker. Woodlice also have two pairs of antennae, with a longer pair used for navigation. They are harmless to humans and pets, as they do not bite, sting, or transmit diseases.
Where Woodlice Live
Woodlice thrive in damp, dark environments, as they rapidly lose water and breathe using specialized respiratory structures. Their natural habitats include moist locations such as under rocks, logs, leaf litter, and compost heaps. They are primarily nocturnal, seeking refuge during the day and emerging at night to search for food.
As detritivores, woodlice play an important ecological role as decomposers, breaking down decaying organic matter. Their diet mainly consists of rotting plant material, such as leaves, bark, fungi, and dead insects. By feeding on this decaying material, woodlice help recycle nutrients back into the soil, contributing to a healthy ecosystem.
Addressing Woodlice in Your Home
Woodlice primarily inhabit outdoor environments, but they may inadvertently enter homes, particularly when seeking moisture or shelter from changing weather conditions. Their presence indoors often indicates underlying dampness or high humidity levels within the structure. They are attracted to humid areas such as basements, bathrooms, laundry rooms, or spaces with water leaks or poor ventilation.
While woodlice are harmless and do not cause structural damage to sound wood or infest food, their appearance can be a nuisance. They might occasionally feed on damp wood or moldy wallpaper, but they are not a significant threat to property. When found indoors, woodlice often die due to the drier conditions of most homes, as they quickly dehydrate.
To address woodlice in your home, focusing on moisture control is an effective non-chemical approach. Fixing leaky pipes, improving ventilation in damp areas, and using dehumidifiers can significantly reduce indoor humidity, making the environment less appealing to them. Maintaining relative humidity below 60% can help limit infestations.
Sealing potential entry points is another important preventative measure. Inspect and seal cracks and gaps around windows, doors, foundations, and where pipes or wires enter the home using caulk or sealant. Clearing organic debris such as decaying leaves, woodpiles, and plant matter from around the foundation of your house also helps eliminate their outdoor habitats near your home. Regularly cleaning gutters and outside drains prevents water buildup that could attract woodlice. For immediate removal, woodlice can simply be vacuumed or swept up and returned outdoors.