Physical Characteristics

The adult pillbug is about 1/4 to 5/8 inches long and has a slatted overlapping armor look to its body. The pillbug is slate gray in color.




Pillbugs are often called roly-polys because they will roll up on a tight ball when disturbed. They’re not really insects, but land-dwelling crustaceans of the order Isopoda, which also includes woodlice. Pillbugs are inactive and hide during the day to conserve water. They’re often found under trash, boards, rocks, flower pots, piles of grass clippings and flowerbed mulch and around building exteriors. Pillbugs gain access indoors via door thresholds and sliding glass doors. Once inside, they usually can’t survive more than a couple of days. The pillbug is a scavenger and feeds on decaying organic matter, and can occasionally injure young plants.


Pillbugs are classified as occasional invaders, and if they’re getting into your house, it’s by mistake. Your Clark technician can point out ways to keep them outside, where they belong. This integrated pest management (IPM) practice is called exclusion.

Latin name: Armadillidium vulgare