Individuals may live for several years. Millipedes are attracted to dark, cool, moist environments, including compost piles, heavily mulched shrub or flower beds, or under logs and stones. They usually go unnoticed because they are active primarily at night. They are scavengers, feeding primarily on decomposing vegetation, but occasionally damaging soft-stemmed plants in gardens. Problems usually occur when the conditions are too dry, and they move to seek out moisture, or else when it's too wet and water-saturated soils force them to the surface and higher ground, often bringing them onto concrete slabs, foundations and siding.
Millipedes also migrate in the fall, presumably in search of overwintering sites.
These periodic migrations result in millipedes invading crawl spaces, basements and the ground levels of buildings. Frequent indoor sightings of these pests usually means that there are large numbers breeding outdoors in the lawn, or beneath mulch, leaf litter or debris close to the foundation. Because of their moisture requirement, they do not survive indoors more than a few days unless they can find suitable conditions. Remove leaves, grass clippings, heavy accumulations of mulch, wooden boards, stones, boxes, and similar items laying on the ground beside the foundation. Prevent water from accumulating near the foundation, in basement walls or in the crawl space.