Millipedes are usually brown to blackish in color. The elongated body is rounded, no flattened, and they have no poison claws or legs. They usually coil up when disturbed, similar to the behavior exhibited by sowbugs or pillbugs.
Common North American species are brownish, one to 2.5 to 4 cm long segmented, with two pair of legs per segment.
Eggs are deposited in the soil. Most species reach sexual maturity in the second year and live several years after that.
Millipedes are usually restricted to moist places where they feed on organic matter. In the fall, they may become a nuisance because they migrate away from feeding areas and invade homes. Because they crawl along the ground, they are usually found in lower floors and basements. Once inside the home, they usually die due to desiccation, although in moist basements, they can survive longer.