Millipedes normally live outdoors but may become nuisance pests indoors by their presence. At certain times of the year (usually late summer and autumn) due to excessive rainfall or even drought, a few or hundreds or more leave the soil and crawl into houses, basements, first-floor rooms, up foundation walls, into living rooms, up side walls and drop from the ceilings. Some homeowners as early as late June have reported annoying populations accumulating in swimming pools.
Fall migrations during rainy and cool weather may result as a natural urge to seek hibernation quarters. Heavy continuous rainfall in newly developed wooded areas with virgin soil (decaying organic matter habitats) are often troublesome sites.
Millipedes do not bite humans nor damage structures, household possessions or foods. They can give off a disagreeable odor and if crushed, leave an unsightly mess.
Millipedes, or "thousand-legged worms", are brownish-black or mottled with shades of orange, red or brown, and are cylindrical (wormlike) or slightly flattened, elongated animals, most of which have two pairs of legs per body segment, except for the first three segments which have only one pair of legs. Antennae are short, usually seven-segmented, and the head is rounded with no poison jaws. Their short legs ripple in waves as they glide over a surface. They often curl up into a tight "C" shape, like a watch spring, and remain motionless when touched. They range from 1/2" — 1-1/4" long depending on the species. They crawl slowly and protect themselves by means of glands that secrete an unpleasant odor.
Read also: Centipede