Texas is home to a significant population of the Nine-banded Armadillo, Dasypus novemcinctus. This unique mammal is easily identified by its protective, bony shell, which covers its back, head, and tail, giving it the Spanish name meaning “little armored one.” The Nine-banded Armadillo is so common and distinctive in the state that it holds the designation of the official small mammal of Texas.
Geographical Spread and Migration
The armadillo is a relatively recent arrival to the United States, with its presence recorded in Texas as far back as 1849, following a natural northward expansion from its ancestral range in South and Central America. After crossing the Rio Grande in the late 19th century, the species began moving north and east through the state, establishing itself as a permanent resident. The expansion rate was estimated to be between 4 and 10 kilometers per year, with major river systems acting as natural dispersal conduits.
Armadillos are now common throughout central and East Texas, where conditions are favorable for their subterranean habits. Their distribution across the state is closely tied to soil moisture and consistency, as they require ground that is soft enough to dig both burrows and forage for food. Consequently, their range stops short of the most arid areas, excluding the western High Plains and the Trans-Pecos regions. The animals struggle in areas with hard-packed clay soils or prolonged freezing temperatures, which limits their northern and western boundaries.
The Nine-Banded Identity: Behavior and Diet
The Texas armadillo is an insectivore, relying on a highly developed sense of smell to locate its food below the surface of the soil. Its diet consists primarily of small invertebrates, including grubs, beetles, ants, and termites, which it excavates using its powerful claws and long snout. The armadillo’s digging behavior involves rooting through loose soil and leaf litter to expose its prey before quickly lapping it up with a sticky tongue.
As a largely nocturnal and solitary animal, the armadillo typically emerges at dusk to forage, though it may be active during the day in cooler weather. Its protective shell, or carapace, is segmented with nine flexible bands, which allow the animal to move and bend. When startled, the armadillo does not roll into a ball. Instead, it leaps straight into the air, an action that often proves fatal when encountered on roadways.
A unique biological feature of the Nine-banded Armadillo is its reproductive cycle, which involves a phenomenon called obligate polyembryony. After mating, the female exhibits a period of delayed implantation. Once gestation begins, she consistently gives birth to a set of four genetically identical quadruplets. These young, which are always the same sex, develop from a single fertilized egg and are born fully formed in the spring.
Armadillos and Public Interaction
The armadillo’s constant need to dig for food and shelter frequently brings it into conflict with Texans, earning it a reputation as a nuisance animal. An individual animal may maintain up to a dozen burrows within its home range, creating holes that can damage lawns, gardens, and structural foundations near homes. The most common sign of their presence is the small, shallow, conical holes left behind in turf as they probe for subterranean invertebrates like white grubs.
Armadillos are notable because they are one of the few non-human mammals that can naturally contract and carry the bacterium Mycobacterium leprae, which causes Hansen’s disease (leprosy). Studies have confirmed a genetic link between the bacteria strains found in armadillos and those in some human patients in the southern United States, including Texas. However, the risk of transmission to humans is extremely low, as most of the human population is naturally immune to the bacteria.
Transmission to humans usually requires frequent, close contact with the infected animal, such as through hunting, handling, or butchering. Simply touching a wild armadillo is not considered a significant risk. Health officials recommend avoiding direct contact with the animals and refraining from consuming armadillo meat to minimize potential exposure. In Texas, the state has made it illegal to sell or transport live armadillos due to this health concern.