The armadillo is one of Texas’s most recognizable mammals, known for its distinctive armored shell and nocturnal habits. While about twenty species exist across Central and South America, only one has successfully established a permanent population in the United States. This single species is the one people encounter most often across the Lone Star State. Understanding this particular species is key to appreciating its role in the state’s ecosystem.
The Nine-banded Armadillo: Texas’s Sole Resident
The sole armadillo species in Texas is the Nine-banded Armadillo (Dasypus novemcinctus). This mammal is a relatively recent addition to the state’s fauna, having expanded its range northward from Central and South America over the last century. Its tough, bony shell, called a carapace, is composed of ossified dermal scutes covered by keratinized scales. The name “Nine-banded” refers to the flexible joints across the midsection of the shell.
Adults are considered cat-sized mammals, typically weighing between 8 and 17 pounds. Including its long, tapering tail, an adult can reach up to 42 inches in total length. The flexible bands across the midsection allow the animal necessary movement for foraging. However, the actual number of bands is not always nine and can vary geographically.
The Nine-banded Armadillo is the largest and most widespread armadillo species globally. Unlike some South American relatives, this species cannot roll completely into a ball for defense. Its primary protection is its heavy shell, which deters most common predators, though it offers little defense against automobiles. Due to its widespread presence, the Nine-banded Armadillo has been designated the official state small mammal of Texas.
Habits and Home Range
The armadillo’s habits are closely tied to its specialized diet of invertebrates. They are insectivores that use their sensitive sense of smell to locate prey up to eight inches beneath the soil. Their diet primarily includes grubs, beetles, ants, and termites, which they lap up with a long, sticky tongue. This foraging behavior is considered beneficial because they consume large quantities of damaging lawn pests, such as white grubs and fire ant larvae.
Their activity patterns are flexible, shifting between nocturnal and diurnal based on temperature. During hot Texas summers, they are active at night to avoid the heat, but in colder winter months, they become more active during the warmest parts of the day. Since they lack significant body fat and cannot hibernate, they must forage frequently; prolonged cold can be fatal. Their range expansion depends on the availability of soft, moist soil, which is necessary for digging and finding food.
The Nine-banded Armadillo is a prolific burrower, creating extensive underground tunnels for shelter and nesting. A single animal may maintain up to a dozen burrows within its home range, with tunnels sometimes reaching 25 feet in length. These burrows are typically simple, averaging about 8 inches in diameter and up to 4 feet deep. Their dependence on soft soil and rainfall prevents them from establishing permanent populations in the arid western Trans-Pecos regions of Texas.
A unique biological feature of this species is its reproductive cycle, known as obligate monozygotic polyembryony. Following mating in the summer, the fertilized egg undergoes delayed implantation, remaining dormant until around November. The single fertilized egg then divides to produce four identical embryos. This process almost always results in the birth of identical quadruplets, all of the same sex, typically born in the spring.
Management and Misconceptions
As the Nine-banded Armadillo has expanded its territory across Texas, it has become a focus of wildlife management. The animal is not a protected species and is classified as a nuisance due to the damage its extensive digging causes to lawns, gardens, and infrastructure. Its tendency to create shallow foraging pits and deeper burrows is the source of most human-wildlife conflict.
One concern involves the armadillo’s ability to carry the bacteria Mycobacterium leprae, which causes Hansen’s disease (leprosy). Armadillos are one of the few mammals, besides humans, naturally susceptible to this disease and are often used in medical research. While a percentage of the wild population carries the bacteria, the risk of transmission to humans is low, requiring prolonged, direct contact. Simple precautions, such as avoiding contact and wearing gloves if handling one, mitigate potential risk.
Several misconceptions exist about the armadillo’s behavior, including the belief that they can roll into a protective ball. This ability is exclusive to the smaller, three-banded armadillo species found only in South America. Another frequent observation is their tendency to jump vertically when startled, a reaction that often leads to them being struck by vehicles. Management of armadillos in Texas focuses on control methods for nuisance animals, primarily through trapping, rather than conservation efforts.