Millipedes like dark, damp climates and high moisture so they will generally live underneath debris piles, mulch, or soil. They feed on decaying vegetation so any areas, like crawl spaces, that have dead leaves or damp and decaying wood are attractive to millipedes. They may enter a home or building if their outdoor climate becomes too dry and warm. Once inside, they’ll hide under boxes or furniture. They will not live long, though, as indoor areas do not generally have exceptionally damp environments or decaying vegetation for them to feed on.