Pill bugs get their name from their habit of curling into a ball when they are disturbed. Some people call them “roly polies” for the same reason. There are pill bugs throughout the world. The most common pill bug in the United States is Armadillidium vulgare (Latreille).
Despite the name, pill bugs are not really bugs. They are land-dwelling crustaceans in the order Isopoda.
Pill bugs usually live in areas where there is high moisture. Their bodies do not hold water. Because of that, they stay hidden during the day and are active at night. They commonly live under landscape timbers and flowerbed mulch. It is common to find them under flowerpots and trashcans.
Pill bugs are scavengers. They eat decaying plant material. They sometimes damage young plants. They also eat animal material if they find it.
Pill bugs often invade homes through sliding glass doors and other ground-level entrances. They also enter garages and storage buildings.
Pill bugs do not bite people. They do not damage household items or deposit eggs indoors. Often, the indoor environment is too dry for them and they die after coming inside.
The first step in preventing pill bugs is reducing the moisture around the home. Mulch in flowerbeds should be no deeper then 2 in. Homeowners should pull mulch away from the home’s foundation. A “dry zone” of 6 to 12 inches around the foundation will discourage pill bugs and other pests.
Firewood should be stacked off the ground. It should be as far away from the house as possible. Flowerpots should be on racks or stands off the ground. Gutters and downspouts should drain away from the foundation. It may be necessary to trim tree limbs if they cause a damp shady area near the home.
Crawlspace vents should be unblocked to allow air circulation. This can reduce dampness. Very damp basements may require a dehumidifier.
The local pest control professional can apply liquid and granular insecticides according to the situation.