Centipede & Millipede

General:

Centipedes and Millipedes are often seen in and around gardens and may be found wandering into homes. Unlike insects, which have three clearly defined body sections and three pairs of legs, they have numerous body segments and numerous legs. Like insects, they belong to the largest group in the animal kingdom, the arthropods, which have jointed bodies and legs and no backbone. Their bodies are covered with a shell-like covering called an exoskeleton. There are several features that distinguish a millipede from a centipede.

Centipedes or "hundred-leggers," are elongated, flattened animals, bearing one pair of legs per body segment. The actual total number of legs in most species is closer to 30 than to 100. Adult centipedes are usually brownish and over 1 inch in length. The house centipede, a species that commonly invades buildings, has long legs that enable it to run rapidly. Unlike millipedes, centipedes never coil up when disturbed.

Habitat and Importance
Centipedes usually are found in damp, dark places, such as under stones, leaf mulch, or logs. Indoors, centipedes may occur in damp areas of basements, closets, or bathrooms, or anywhere in the home where insects occur. During the day they hide in dark cracks and crevices, coming out at night to search for insects to eat.

House centipedes are actually beneficial--they capture flies, cockroaches, and other small household pests. They never damage plants or household items.

When provoked, a few large kinds of centipedes can inflict a painful bite that may cause localized swelling, discoloration, and numbness.

Life Cycle
Adult centipedes winter in secluded moist places. Eggs are usually placed in damp soil in the spring and summer. Some centipede species add segments and legs as they grow; others are born with a complete set. Centipedes require 2 to 3 years to mature, and have been known to live 6 years.

Millipedes, or "thousand-leggers," are brownish, elongated, cylindrical to slightly flattened creatures, with two (most common) or four pairs of tiny legs per body segment. Millipedes don't really have a thousand legs; even the largest ones have somewhat less than a hundred. When they walk, their legs move in an undulating wavelike manner. Adult millipedes vary from 1/2 to 6 1/2 inches in length. When prodded or at rest, most millipedes curl up.

Habitat and Importance
Millipedes normally live in and feed on rotting leaves and wood and other kinds of moist decaying plant matter. Generally, their role is a beneficial one in helping to break down dead plant matter. However, when they become numerous, they may damage sprouting seeds, seedlings, or strawberries and other ripening fruits in contact with the ground.

Sometimes individual millipedes wander from their moist living places into homes, but they usually die quickly because of the dry conditions and lack of food. Occasionally, large numbers of millipedes migrate, often uphill, as their food supply dwindles or their living places become either too wet or too dry. They may fall into swimming pools and drown.

When disturbed they do not bite, but some species exude a defensive liquid that can irritate skin or burn the eyes.

Life Cycle
Adult millipedes winter in the soil. Eggs are laid in clutches beneath the soil surface. The young grow gradually in size, adding segments and legs as they mature. They mature in 2 to 5 years and continue to live for several years thereafter.