Pill Bug

Family Name

Class Crustacea, Order Isopoda





Up to 0.5 inch.




Commonly known as roly-polies, pill bugs are usually nocturnal and feed on decaying vegetable matter. Where large numbers occur outside a foundation, numerous pill bugs may find their way inside where they quickly die from dehydration. They can survive nicely in damp basements, cellars and crawl spaces. They have been found living within homes where a constant moisture source is available due to a water leak.


Pill bugs prefer moist environments and are found under objects lying on the damp ground and within leaf litter, mulch and other types of vegetative debris.

Tips for Control

Pill bug indoor invasions occur when conditions outside support large numbers of these crustaceans. Treatments can provide short-term relief, but correction of such conditions is key to long-term success. Thick ground covers, such as ivy, “monkey” grass, etc. should not be located next to or near a foundation as it provides harbourage for innumerable insects, spiders, mice and other pests. Items in contact with the soil should be removed, wherever possible. Firewood, lumber and other such stored items should be stacked off the ground on supports away from the building. Exterior cracks and holes should be sealed, especially along the foundation. Weep holes can be “closed” by stuffing pieces of wire mesh or screening into the openings. Inside treatments usually are not needed, because pill bugs dry out quickly and die.