The nine-banded armadillo, Dasypus novemcinctus, is the only armadillo species regularly found in the United States, distinguished by the bony, protective plates that cover its body. Originating in South and Central America, this mammal has undergone a remarkable expansion across the southern and eastern portions of the country over the last century and a half. Understanding where armadillos live in the US requires a look at their current established range, the history of their migration, and the environmental factors that ultimately limit their spread.
Current Established Territories
The core population of the nine-banded armadillo is concentrated across the southeastern United States, establishing a strong presence throughout Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida. This range extends westward into Oklahoma and Arkansas, forming the dense heart of their US distribution.
The habitat in these regions provides the warm, humid, and often forested conditions that closely resemble the armadillo’s ancestral home. From these southern strongholds, armadillos have continued to push their boundaries, establishing newer populations in states further north and east. This expansion now includes the entirety of Missouri, most of South Carolina, and significant portions of Tennessee and Kentucky. Recent reports also confirm established populations reaching into southern Illinois, southern Iowa, and the western third of North Carolina.
The Historical Spread Across the US
The armadillo’s presence in the US is relatively recent, with the species first recorded in Texas around the mid-1800s after crossing the Rio Grande from Mexico. By the 1930s, the species had spread across most of Texas and into neighboring Louisiana and Oklahoma.
A separate, significant population was established in Florida through human introduction, occurring around the same time as the natural expansion from Mexico. These two distinct groups merged and fueled the rapid expansion throughout the Southeast. The construction of roads, bridges, and other human-made corridors aided the species by providing travel routes that bypassed natural obstacles like large rivers.
Environmental Limits to Expansion
The primary factor dictating the armadillo’s northern and western boundaries is their low tolerance for sustained cold temperatures. They lack the thick layer of fat or dense fur that allows many other mammals to effectively thermoregulate in cold weather. As a result, the armadillo cannot establish stable, breeding populations in areas where the average January temperature drops below approximately $-2^\circ$C or where there are more than 24 annual days of freezing temperatures.
Their need for specific ground conditions also creates a geographical limit, particularly to the west. Armadillos are extensive burrowers, requiring loose, moist soil for both shelter and foraging, and cannot survive in areas where the ground is too hard to dig. This necessity for adequate rainfall prevents them from migrating into the arid, desert regions of the southwestern US, such as New Mexico, creating a western boundary.
Living Conditions and Diet
Within their established ranges, armadillos seek out habitats like dense shady woodlands, pine forests, and scrublands that offer ample cover and loose soil. They are solitary and primarily nocturnal.
Using their strong sense of smell to locate food below the surface, they rely heavily on their nose, held close to the ground, due to poor eyesight.
The nine-banded armadillo is an insectivore, with its diet consisting mainly of small invertebrates, including ants, adult and larval beetles, grubs, and termites. They forage by thrusting their snouts into the soil and digging with sharp claws, then using their long, sticky tongue to lap up their prey.