Millipedes: Diplopoda

Physical characteristics: Pill millipedes are short and either dark brown or black. Their twelve body segments are dome-shaped in cross section. They have light brown or light gray margins toward the rear. Adults have seventeen to nineteen pairs of legs and reach 0.8 inches (20 millimeters) in length and 0.3 inches (8 millimeters) in width.

Geographic range: This species is found in the British Isles and in western and northwestern Europe.

Habitat: Pill millipedes are found in forests, fields, and gardens, usually in leaf litter. Unlike most millipedes, Glomeris marginata is better equipped to deal with drier conditions. It is often active on bright, sunny days.

Pill millipedes are found in the British Isles and in western and northwestern Europe. (Illustration by Amanda Humphrey. Reproduced by permission.)

Diet: Pill millipedes eat decaying leaves. A study in France showed that they eat about one of every ten leaves that falls to the forest floor each autumn.

Behavior and reproduction: When threatened they roll up into a ball, just like a pillbug. They also produce a chemical that makes them smell and taste bad to most predators (PREH-duh-ters), or animals that hunt other animals for food.

Males produce pheromones (FEH-re-moans), or chemicals that are attractive to females. They also make a squeaking sound to get females to mate with them.

Females lay six or seven dozen eggs in spring and again in summer. Each egg is deposited in a capsule. The young molt once inside the egg before they hatch about two months later. Cooler temperatures can delay hatching up to several months. The young take several years to reach adulthood. They may live up to a total of eleven years. Females may produce a dozen batches of eggs during their long life.

Pill millipedes and people: This species is important because it breaks down and recycles dead leaves and other vegetable matter.

Conservation status: This species is not considered endangered or threatened. ∎