14 families globally, 4 families in North America north of Mexico, in the order Geophilomorpha (soil centipedes)
There are many species of soil centipedes. They range in color from reddish brown to nearly white and have slender bodies. Often their bodies are flattened top to bottom. They have between 27 and 191 pairs of legs, depending on the species.
Centipedes always have an odd number of pairs of legs, and only one pair of legs per leg-bearing body segment.
Soil centipedes lack eyes and are sightless. They move through the soil like earthworms, by expanding their length forward, then contracting to draw the hind part of the body toward the head.
Length: ¾–7¾ inches (depending on species and age).
Soil centipedes occur in many types of habitats. They burrow into the soil much like earthworms do and are found in gardens, yards, woodlands, agricultural ground, and elsewhere. They are commonly encountered under rocks, logs, and other protected areas.
All centipedes are predators. They specialize in insect larvae and earthworms. Like spiders, they have fanglike appendages that are usually equipped with venom glands that help them subdue their prey. Missouri's soil centipedes are too small to harm us.
Many species within this order exhibit parental care of the eggs and sometimes the hatchlings. The female lays 15–60 eggs in the soil or in rotten wood. She stays with the eggs, guarding and licking them to protect them from fungi. If the female is severely disturbed, she will often abandon the eggs or eat them. Eggs that have been abandoned rarely survive to hatch as they are usually consumed by fungi.
Soil centipedes influence the soil in ways that benefit humans. Also, they cannot bite people and therefore are harmless to humans.
These centipedes consume a tremendous amount of soil-dwelling larvae. Their tunneling aerates the soil, allowing water and nutrients to reach the roots of plants and grasses.
Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.