Though our subject here is the species Orthoporus ornatus, there are other Orthoporus species that are commonly referred to as the "Desert Millipede", and Orthoporus ornatus goes by a variety of other common names including Ornate Millipede, Sonoran Millipede," and Texas Striped Millipede. The Desert Millipedes (Orthoporus spp.) are native to North and South America, where they inhabit warmer, drier areas than is typical of millipedes. These are fairy large, hardy, and unusual millipedes that can make interesting additions to any arthropod collection.

The Desert Millipede differs from most other millipedes in that it inhabits desert regions, rather than humid areas. Though they are a desert species they still require fairly high humidity levels and cannot tolerate extreme heat. They protect themselves from the harsh climate by remaining in somewhat moist microhabitats, such as underground burrows, most of the time, emerging only at night or after it rains. These are slow-moving creatures that spend most of their time hidden in burrows, and come out at night to feed on decaying plant matter. When threatened, a millipede will curl up into a tight coil and may secrete a liquid irritant from the sides of its body. While this substance is not particularly dangerous to humans, it can irritate the skin and mucous membranes it comes in contact with, and some people may be more sensitive to it than others.

Desert Millipedes are relatively large millipedes that can be expected to reach lengths of between anywhere from 3.5 to 7 inches, with lengths between 4 and 6 inches being the most common. They are cylindrically shaped with 2 pairs of legs on each segment of the body. The coloration of this species varies throughout its range, but is most often some shade of brown, ranging from yellowish to nearly black in its overall color. They may be bright orange, brownish orange, or reddish brown, and some have black stripes on a light base color.

There appears to be some debate concerning the taxonomy of the various Orthoporus species, making it difficult to determine a precise range for particular species. Many sources classify species found in Arizona, Texas, and New Mexico as Orthoporus ornatus, while others limit it to a small range in Southern Arizona.

Desert Millipedes can be housed singly or in groups. They do not require large enclosures and one or two adults can easily be kept in a 5 gallon terrarium. The cage size can be smaller or larger depending on the size and number of millipedes being housed together. The substrate should be something they can easily burrow in and that will help retain some humidity such as soil or peat moss. Appropriate daytime temperatures are between 80 degrees and 85 degrees Fahrenheit, and at night the temperature can drop to about 75 degrees. They humidity level should be about 75% to 80%. Humidity levels can often be maintained with regular misting. Desert Millipedes can be offered a variety of fruits and vegetables such as cucumbers, apples, and leafy green vegetables. It is recommended that their food be dusted with a calcium supplement.

Desert Millipedes reportedly breed readily in captivity. The babies do not grow as quickly as many other millipedes.