These large millipedes occur primarily in the hotter, drier regions of the south and southwest U.S. They differ from typical millipedes in that they have only a single pair of legs on each of the first five body segments, whereas typical millipedes have 2 pairs of legs on each body segment. They typically are large species that may grow to more than 6 inches in length. They are scavengers that feed on dead plant and animal materials and thus are important in recycling these materials. When disturbed they coil into a tight spiral and may ooze out an oily fluid from glands near where the legs attach. This fluid is foul tasting but also toxic to any animal that attempts to eat the millipede.
When found in natural settings or even landscape these millipedes do not need to be killed. They perform a valuable role in recycling. The effort should be to prevent their entry into structures with good exclusion.