Adults grow to about 3/8 inch long. They have a number of rounded body segments and seven pairs of legs. Sowbugs possess a pair of tail-like structures on the back end of the body. Pillbugs do not have these structures and are capable of rolling into a tight ball when disturbed (a behavior that resulted in their common name, “roly-polies”.)
Sowbugs and pillbugs are inactive during the day. They prefer to hide in damp dark places such as underneath stones, logs, leaf litter and other debris during bright daylight hours. At night they venture out and feed on decomposing organic material, including mulch and grass clippings. They will feed on the tender foliage, stems and roots of young garden vegetable transplants, seedlings and bedding plants. They generally enter structures through doors on ground level.
Both pillbugs and sowbugs are scavengers, and feed on decaying organic matter, both plant and animal.
Life cycle and Reproduction
Females lay eggs that they carry in a pouch underneath the body. Eggs hatch into young sowbugs and pillbugs that resemble adults but are smaller. They remain in the pouch up to 2 months after hatching. Complete development occurs in about a year. They may live up to 3 years. Up to three broods may be produced annually.
Mainly a nuisance, particularly when they venture indoors; capable of feeding on tender plant tissue and occasionally causing considerable damage to garden transplants and seedlings; medically harmless.