Armadillos, whose name translates to “little armored one” in Spanish, have evolved a range of defenses. These strategies extend beyond their shell, helping them survive encounters with predators.
The Armored Shell
The armadillo’s shell is its primary defense, a complex structure of dermal bone plates called osteoderms. These osteoderms develop within the skin, forming a mosaic of interconnected tiles. They are covered by a tough keratin layer, similar to human fingernails, which forms scales or scutes. This combination resists crushing forces and environmental wear.
The shell is not a single, solid piece but is divided into distinct sections, allowing flexibility. Most species, including the common nine-banded armadillo, feature large, solid shields over their shoulder and pelvic regions, connected by flexible bands. While this allows movement, the nine-banded armadillo cannot fully roll into a ball. In contrast, only the three-banded armadillo can curl completely into a tight, impenetrable sphere, fitting its head and tail together like a puzzle piece.
Behavioral Defenses
Beyond their passive armor, armadillos employ active behaviors when faced with danger. A common tactic is rapid burrowing, facilitated by their strong claws and powerful forelegs. They quickly excavate a shallow trench and hunker down, wedging themselves firmly into the earth with their armored back exposed. This makes it difficult for a predator to dislodge them and protects their unarmored underside.
Some armadillo species, like the three-banded armadillo, actively roll into a ball when threatened. Another defense, particularly noted in the nine-banded armadillo, is a sudden vertical jump of 3 to 4 feet when startled. This reflexive leap can disorient a potential predator, providing a brief moment for the armadillo to escape by running or burrowing.
Effectiveness Against Predators
Armadillo defenses are effective against many natural predators, including coyotes, bobcats, foxes, and large birds of prey. The armored shell deters many attackers, making them a less appealing target. While their shell offers significant protection, it is not entirely impenetrable, and determined predators can sometimes overcome it.
The behavioral responses also have limitations. The armadillo’s “startle jump,” while disorienting to predators, can be a disadvantage in developed areas. Armadillos frequently jump into the undercarriage of moving vehicles when startled by cars, leading to high road mortality. This highlights how a defense mechanism adapted for natural environments can become a vulnerability in human-modified landscapes.