Sowbugs can be separated from the pillbugs by the fact that they cannot roll up into a tight ball like a pillbug. As well, the sowbug has two tail-like appendages that the pillbug does not have. Sowbugs and pillbugs are the only crustaceans that have completely adapted to spending their whole life on land. They have oval bodies, convex above and flat or hollow beneath. The common pillbug and the dooryard sowbug are worldwide in distribution. They like moist locations and are found under objects on damp ground, as well as under vegetable debris of all kinds. They are mostly active at night.
Sowbugs and pillbugs will at times invade damp basement areas as well as the first floors of houses. When this occurs they are most likely always present in large numbers in the soil and under plants immediately outside the house. Generally sowbugs and pillbugs do not live long inside as they dry out quickly. Sowbugs and pillbugs normally feed on decaying vegetable matter.