Millipedes usually have 30-90+ pair of legs. They are widely distributed throughout the United States and most of the world, with about 1,000 species occurring in the U.S.
Adults are about 1/16th - 4 1/2" long usually cylindrical and wormlike but some are slightly flattened. Their color is usually blackish or brownish but some are with red, orange or mottled patterns. Each has one pair of short 7-segmented antennae. Body segments bear 2 pairs of legs, except first 3-4 segments and last 1-3 segments, which have 1 pair or no legs at all.
Millipedes overwinter as adults or young. Adult females lay 20-300 eggs, either in soil cavities or among decaying organic matter during the summer. Eggs hatch after several weeks. In most species there are 7-10 molts. In many species sexual maturity is not reached until the second year. They eat their molted skins to restore lost supplies of calcium. Adults often live for several years.
Millipedes have high moisture needs, like pillbugs and sowbugs. They are typically found in areas of high moisture and decaying vegetation such as under trash, piles of grass clippings flowerbed mules, leaf litter, etc. Millipedes are nocturnal and active at night. Sometimes, and usually in autumn, millipedes will migrate in great numbers. This can involve several hundred to several hundreds of thousands of millipedes. They usually do not survive indoors for more than a few days unless there are high moisture conditions and a food supply present. Millipedes are primarily scavengers and feed on decaying organic matter, usually plant material, but occasionally on dead insects, earthworms and snails. They may attack living plants during dry periods in order to obtain needed moisture.
The key to controlling millipedes is to reduce or eliminate the moist areas, which make their survival possible. Outdoors one should de-thatch the lawn because dense lawns hold excessive amounts of moisture. Mow the lawn closely at edges as this promotes quicker drying of the lawn. Remove all debris such as accumulations of leaves and wood debris, rocks, heavy mulch. Firewood should be stored off the ground and provide adequate ventilation to all sub-area crawl spaces of the home to eliminate all damp sheltered areas and hiding places. Water lawns in the early morning instead of evenings to allow the grass to dry during the day.
If populations remain in excess then a call to Long Pest Control can develop an Integrated Pest Control program to eliminate the sightings and provide an environment free of unwanted ground crawling insects year round.