Appearance & Identification
What do millipedes look like?

Size
With a long, cylindrical, segmented body, millipedes may reach up to 1-1/4 inches long and up to 3/16 of an inch thick.
Body
Millipedes possess spiracles (holes or openings) on each body segment, which the diplopods use to breathe.
Legs
Millipedes have two pairs of legs attached to each body segment. Males typically have longer legs and antennae than females
Color
Though generally black in color, other individuals of the species may show a range of colors along the edges of the body segments, including yellow, pink, and even purple.
Certain species of millipedes may secrete a yellowish liquid as a defense mechanism that is generally harmless to humans, though it may leave red marks on the skin.
Facts
Resembling a worm with legs at first glance, millipedes are elongated invertebrates that typically feed on detritus (rotting organic material). Though the name implies that the animal possesses 1,000 legs, most millipedes typically have fewer than 50 pairs. Found in cool, damp, and dark environments, millipedes are a segmented diplopod that may become a nuisance around the house.
Generally beneficial, as the animals feed on decaying organic matter, millipedes may take up residence in garages, sheds, or basements.
Habits/Habitat
The North American millipede, or Narceus americanus, as well as several sub-species, may be found throughout the United States, especially in the eastern part of the country. Millipedes may be found in both urban and suburban areas living under rocks, dead trees, leaf piles, and typically anywhere the soil is damp and the humidity remains high. Typically solitary and nocturnal, the millipede is capable of forward, backward, and sideways movement, as the pairs of legs move simultaneously down the body. Millipedes are also expert burrowers. If threatened, the diplopod may curl into a tight spiral, using the hard exoskeleton to protect itself from potential predators.
Diet
What do millipedes eat?
As detritivores, or animals that prefer to eat detritus and other decomposing debris, millipedes are known to feed on decaying leaves, wood, and roots.
In addition, the diplopod will eat bacteria and developing fungi. Millipedes also feed on their own waste in order to further glean nutrients not gathered the first time. On occasion, the diplopod may feed on living plant roots or developing vegetation.
Reproduction
Starting in the late spring or early summer, millipedes mate and usually lay 100 eggs or more. Females tend to burrow into the soil to dig a nest where the eggs will be deposited. Young millipedes hatch after two to ten weeks of gestation and must complete seven stages of growth. When molting, the diplopod adds segments and legs to the body, and the maturation process may take up to one year. The millipede reaches sexual maturation at one year. Millipedes may live up to five years, while the average lifespan ranging around two years.
Problems Caused by Millipedes
Millipedes are commonly classified as a nuisance pest. When the habitat of the animal floods or becomes inhospitable for any reason, millipedes may migrate and find ways into homes and other structures. Garages and basements often make perfect domiciles for the diplopod, as both offer dark and potentially damp surfaces and hiding places. In some cases, when threatened, the millipede will discharge a substance that may irritate or discolor human skin. Certain subspecies may also act as carriers of mites, which may be vectors of certain diseases.
Signs of Infestation
The most obvious sign of infestation remains physically seeing millipedes in the home or workplace. As millipedes are primarily nocturnal, the possibility of seeing the animals may not occur all at once. Millipedes may hide in boxes, under shelving, in mulch beds around the home, and even under sinks, where moisture may accumulate. Millipedes remain harmless to both people and pets in most situations.
Prevention
The best way to prevent a millipede infestation remains closing off/sealing points of entry. Cracks in foundations, openings around pipes and cables, and window sills and doorways may provide access to the home or business. The best way to keep millipedes out of the home is exclusion. Utilize caulk around windows and doorframes, pack areas around cable, wires, and piping with mesh wiring, and always repair cracks in foundations when found. In cases of extreme infestation, home and business owners may wish to contact a trained pest control professional to properly eliminate the millipede problem.