Armadillos are present in Missouri, and their population is steadily expanding across the state. The species found here is the nine-banded armadillo (Dasypus novemcinctus), which is the only armadillo species found in the United States. This mammal, whose name translates from Spanish as “little armored one,” has established a firm presence, particularly in the southern regions.
Identifying the Nine-banded Armadillo
The nine-banded armadillo is unmistakable, covered by a bony, segmented armor called a carapace that makes up about 16% of its body weight. This armor is divided into two large plates over the shoulders and rump, connected by a series of flexible bands, typically nine, around the midsection. Their average size is comparable to a large house cat, measuring between 23 and 31 inches long, including the tail. They typically weigh between 11 and 14 pounds.
The armadillo’s reproduction is unique among mammals due to obligate polyembryony. A single fertilized egg divides to produce four genetically identical young, always of the same sex, born as identical quadruplets. Females also use delayed implantation, where the embryo remains dormant for a few months after summer breeding. This ensures the young are born in the relative warmth of early spring. Armadillos have poor eyesight and a low body temperature (89 to 95 degrees Fahrenheit), relying heavily on a keen sense of smell to forage for insects and grubs.
The History of Their Spread into Missouri
The nine-banded armadillo is not native to North America. It began its northward migration from Central and South America, crossing the Rio Grande into Texas in the mid-1800s. From Texas, the species expanded north and east through the Deep South, moving through Arkansas before establishing a presence in Missouri. Sightings in Missouri started becoming common around the 1980s, marking the beginning of their establishment.
Expansion was historically limited by cold winter temperatures because armadillos have little body fat and cannot tolerate freezing conditions for long periods. They are not adapted to find food when the ground is frozen, as they forage for invertebrates beneath the soil surface. Increasingly warmer winters over the past few decades have allowed the species to survive the cold season in previously harsh regions. This climatic shift has been a significant factor enabling their successful establishment and continued movement north, surpassing previous predictions of their northern range limit.
Current Distribution and Habitat
The armadillo’s range is still expanding, but the densest populations are concentrated in the southern half of Missouri, particularly in the Ozarks region. This area provides preferred wooded habitats, such as oak-hickory or shortleaf pine forests. Sightings have become increasingly frequent, and the armadillo has been documented as far north as the Missouri-Iowa state line and across the Missouri River, pushing the predicted northern boundary.
Their preferred habitat must offer loose, soft soil that is easy to excavate, as they are prolific burrowers. Armadillos create extensive burrows, which can be up to 20 feet long and 7 feet deep, for shelter and nesting. They are often found in bottomland areas, brushy zones, and riparian corridors near water sources, where the soil is typically moist and easily dug. Soft soil is a primary determinant of their distribution, as they cannot survive where the ground is too hard to dig for shelter or food.
Interaction with People and Property
The most common interaction people have with armadillos involves the damage they cause while foraging for food. Armadillos root through lawns and gardens in search of insects, grubs, and worms, leaving behind characteristic shallow, cone-shaped holes that are typically one to three inches deep. This digging activity can be a significant nuisance, resulting in torn-up turf and damage to plant roots. They can also cause structural issues by burrowing under foundations, driveways, and other concrete structures.
A public concern surrounding armadillos is their potential to carry the bacteria Mycobacterium leprae, which is associated with Hansen’s disease (leprosy). Because the armadillo’s naturally low body temperature allows the bacteria to thrive, they are one of the few non-human animals capable of carrying it. However, the risk of transmission to humans in Missouri is extremely low, as most people have a natural immunity to the disease, and confirmed cases are rare. Wildlife experts recommend wearing gloves if handling an armadillo and avoiding consumption of armadillo meat as a basic precaution.