More than 900 species in North America north of Mexico

About 52 families in the class Diplopoda (millipedes) in North America north of Mexico; in the phylum Arthropoda


Millipedes are long, segmented animals that are most typically round in cross-section (not flattened). They are generally slow-moving. Apart from the first three body segments (which each have one pair of legs), and the head and tail, all the remaining body segments have two pairs of legs. The number of body segments varies with species, and additional segments are added as the millipedes grows and molts. Most of our species are brown or blackish. Millipedes with bright colors are more likely to secrete foul or toxic substances in defense—the bright coloration is a warning to predators.

Similar animals: Centipedes (class Chilopoda) are usually flattened, move quickly, and have only one pair of legs per body segment. They have pincers, are mostly carnivorous, and are capable of biting.


The largest North American species is about 6 inches long.


image of Xystodesmid Millipede crawling on a forest floor
Xystodesmid Millipede


Photo of millipede crawling on soil at the base of a bunch of grasses.
Prairie Millipede
Millipedes are common, though they are not commonly seen or noticed.
Habitat and conservation

Millipedes are secretive and tend to hide in leaf litter or other moist, dark places, such as under rocks and rotting logs. Millipedes have a long fossil record and represent one of the earliest groups of land-dwelling animals. Apart from eating and reproducing, their most notable behaviors involve defense: They often curl into a coil when disturbed, and some can emit a foul-smelling substance. A few species give off a cyanide-containing secretion when harassed.


A great majority of species in this class of animals are detritus-eaters, softening rotting leaves and other decaying materials with saliva as they chew. A few eat living plants, and some may also be carnivorous or omnivorous.

image of Millipede Distribution Map
Distribution in Missouri



Common, though not commonly seen or noticed. Millipedes are a class of arthropods (jointed-legged invertebrate animals). Other major arthropod classes include the centipedes, the arachnids, the insects, and the various classes of crustaceans.

Life cycle

After mating, female millipedes lay eggs (the number varies with species) on or near the ground, although some build nests. Newly hatched millipedes have few legs and segments. Like other arthropods, millipedes must shed their armorlike exoskeletons in order to grow. As they molt and grow, new body segments and thus more legs are acquired. The lifespan of some species approaches a decade.

Human connections

Millipedes are interesting animals and fun to watch. The hundreds of tiny, paired legs move in an attractive wavelike pattern as they glide over a surface. Many Missourians are scarcely aware that millipedes exist, but they have been an enduring part our world for 400 million years.

Ecosystem connections

Recycling is an ancient concept, and millipedes recycle nutrients when they eat decaying plant material and turn it into millipede flesh. That nourishment moves up the food chain as the millipede is eaten by larger predators.