Centipedes and millipedes live in damp, dark places under logs, stones, rocks, and bark. Millipedes are omnivorous (they eat both animal and vegetable matter) but are predominantly herbivore. Centipedes are more predatory, chasing other small arthropods (insects, for example), which they paralyze by injecting with venom before devouring. Certain species of centipedes can inflict a bite if you aren’t careful.
In the fall, millipedes migrate by the hundreds in search of a place to spend the winter. They can also be seen after a heavy rain, when raised water levels in the ground force them to leave their natural shelters. It is at these times that they can infiltrate dwellings and be seen on exterior walls.