Armadillos are unique mammals found across the Americas, from South America to the southern United States. Their distinctive, unusual body covering sets them apart in the animal kingdom.
The Armadillo’s Distinctive Outer Layer
Armadillos primarily possess a robust, leathery armor shell, not fur. This shell is composed of bony plates called osteoderms, embedded in the skin and covered by overlapping epidermal scales known as scutes. These scutes are made of keratin, the same material found in human fingernails. The osteoderms form five distinct sections: the head, pectoral (shoulder), banded, pelvic (hip), and tail shields.
While armor covers most of their body, armadillos do have some hair. Most species appear largely bald, though some, like the pink fairy armadillo, exhibit more fur, often sparse and wiry on their sides and belly. The screaming hairy armadillo, for example, has noticeable hair protruding from between its scutes and covering its limbs and underside. These hairs can also function as sensory tools, helping armadillos navigate their surroundings, particularly at night. The unarmored underside is typically covered with soft skin and fur.
The Armor’s Role in Survival
The armadillo’s armor protects against various threats. Its tough, mineralized plates provide a formidable defense against predators, making it difficult for many animals to breach their covering. This armor also shields them from thorny vegetation and other environmental hazards as they move through their habitats. When startled, many armadillos quickly dig into the ground, using their shell to protect their vulnerable undersides.
The design of the armadillo’s shell, particularly the banded sections, allows for flexibility. Species like the three-banded armadillo can curl completely into a tight, armored ball when threatened. This ability offers a high level of protection by presenting a nearly impenetrable sphere to predators. Other armadillo species, such as the nine-banded armadillo, rely more on their speed and burrowing capabilities for defense, often jumping several feet in the air when surprised before fleeing or digging.
Beyond physical defense, the armor and burrowing habits also contribute to thermoregulation. Armadillos have a relatively low metabolic rate and limited insulating body fat, making temperature regulation important. Their burrows provide a stable, cooler environment during hot periods and offer refuge from cold weather, helping them maintain a consistent body temperature. The bony plates may help dissipate heat in warm climates, and behavioral adaptations, such as being more active during cooler parts of the day or night, also aid in managing their body temperature.