Just like insects and arachnids, millipedes are categorized as arthropods, but unlike insects and arachnids, millipedes belong to the Diplopoda class. There exists a whopping 10,000 documented millipede species in the world with 1,400 occuring within the United States. However, experts estimate that as many as 80,000 millipedes may exist worldwide. Millipedes generally dwell beneath leaf litter and in soil located in forested areas, but several millipedes in Massachusetts dwell on the sandy coast not far from the ocean’s shore. Although millipedes prefer to dwell within the natural environment, they sometimes swarm into homes and buildings during their migration period or within basements and other moist locations when more ideal natural locations cannot be found. Many millipede species also excrete toxic compounds that can irritate human skin. The most frequently spotted millipede species in Massachusetts is the North American millipede, which residents commonly spot near or within their homes, especially on decks and in basements. Another notable millipede species that has been found in Massachusetts homes is known as Pleuroloma flavipes.

The North American millipede hibernates during the winter, but during the warmer season they migrate aimlessly in massive number where they sometimes stumble upon a home where they do not hesitate to swarm into warm and moist areas, mainly in drains, basements and cellars. North American millipedes migrate across roadways where they can also be a nuisance. In addition to being a nuisance, these millipedes secrete a defensive substance that irritates and discolors skin. Millipedes can easily access homes through gaps under doors, beneath garage doors, windows, and crawl spaces. The Pleuroloma flavipes millipede species has been known to gather in large masses in residential neighborhoods during their midsummer migrations. Understandably, these gatherings have been a concern to residents who found swarms within their homes and businesses. Millipedes quickly dry out and die unless they secure moist and warm conditions, and this is why thousands of dead millipedes can litter roads, neighborhoods and urban centers. Millipede swarms become particularly large during periods of heavy rainfall.

Have you ever found a millipede in your home?