07/30/2026
In one Alabama study, nearly every fire ant mound on the research site showed evidence of an armadillo digging through it. The ants swarmed. The ants stung. The armadillo did not care. A 15-pound mammal wearing bony plates walks up to a colony of venomous insects that can send a grown adult to the emergency room, tears the mound open with claws built for excavation, shoves its long nose into the tunnels, and eats until it is done.
The red imported fire ant arrived in the United States through the port of Mobile, Alabama, sometime in the 1930s. It spread across the southern states and became one of the most destructive invasive insects on the continent. USDA estimates the economic damage at roughly $6 billion per year. A single colony can hold 200,000 to 500,000 workers. When the mound is disturbed, the workers pour out by the thousands, climb the nearest vertical surface, and sting simultaneously. Each sting injects a venom that produces a burning pustule. Enough stings at once can trigger anaphylaxis. People have died. Pets have died. Ground-nesting birds lose entire clutches. Most mammals that accidentally step on a fire ant mound learn the lesson and never step on one again.
The armadillo steps on them on purpose.
The nine-banded armadillo has a shell made of bony plates called osteoderms, overlapping scales of bone beneath a tough leathery hide that covers the animal from the top of the head to the base of the tail. The shell flexes at nine jointed bands across the midsection. It is not impenetrable. A determined coyote or a car tire will get through it. But fire ant mandibles and stingers cannot. A fire ant attacking the dorsal surface of an armadillo is biting bone through leather. The ant's venom, devastating to exposed human skin, does nothing to an animal wearing a suit of armor that evolved 55 million years ago.
The belly is unarmored. The legs have thin skin. The snout is exposed. The armadillo is not invulnerable. But the feeding posture minimizes every vulnerability. When an armadillo digs into a fire ant mound, its nose goes into the hole first. The armored back faces upward. The legs tuck close to the body. The shell takes the swarm while the tongue does the work. The tongue is long, sticky, and probes deep into the tunnels and brood chambers where fire ant larvae and pupae are packed together. The armadillo is not eating adult workers one at a time. It is eating the brood, the nursery, the next generation of the colony, by the mouthful.
The University of Georgia's Natural History Series on the nine-banded armadillo describes the Alabama finding plainly: nearly every fire ant mound on the study site showed evidence of disturbance by armadillos. They seem undeterred by the bite of the fire ant. The word undeterred is doing a lot of work in that sentence. It means the armadillos visited mound after mound across the entire study area and nothing the fire ants did changed the outcome.
The armadillo is not native to most of the territory it now occupies. It has expanded from Texas and Mexico across the entire Southeast over the past century, reaching as far north as southern Illinois and as far east as the Carolinas. It arrived in Alabama around the 1960s. The fire ant arrived in Alabama around the 1930s. The two invasions overlapped on the same landscape, and the armadillo found a food source that nothing else in the ecosystem was willing to touch.
Source: University of Georgia, Warnell School of Forestry and Natural Resources / National Wildlife Federation / USDA APHIS / Florida Fish and Wildlife Conservation Commission / Outdoor Alabama.
