Armadillos, with their distinctive armored appearance, are often associated with the warmer climates of the southern United States. These unique creatures have been steadily expanding their range northward, leading to increased curiosity about their presence in states like Illinois. Their presence raises questions about adaptation to new environments and implications for local ecosystems.
Armadillos Are Expanding into Illinois
Nine-banded armadillos are present in Illinois, particularly in the southern half of the state, where they became common after first being reported in 1979. Sightings are now increasing northward into central Illinois, reaching as far as Morgan, Tazewell, Peoria, and Woodford counties. The Illinois Department of Natural Resources (IDNR) tracks these movements.
An adult armadillo is roughly the size of a large cat, though its body shape resembles an opossum. They are identifiable by their bony plates covered in leathery skin. Armadillos are largely nocturnal, active during the night, and primarily forage for insects. They are known to breed in Illinois, indicating established populations are taking hold.
The Journey Northward
The nine-banded armadillos’ journey into Illinois is part of a broader northward and eastward expansion across the United States. Originating in South and Central America, these animals entered North America approximately 3 million years ago via the Isthmus of Panama. Their significant expansion into the United States began around 1850, when they crossed the Rio Grande from Mexico.
Several factors contribute to this spread. Armadillos have a high reproductive rate, often giving birth to identical quadruplets. Their adaptability also plays a role; they can traverse water bodies by inflating their intestines to float or by walking underwater. The lack of natural predators in newly colonized areas has also allowed their populations to thrive.
Changing environmental conditions have facilitated their movement. Armadillos have little body fat and do not hibernate, making them susceptible to prolonged cold. Milder winters have allowed them to survive in areas previously considered too cold for stable populations, as they cannot establish colonies where the average January temperature falls below 28°F (-2°C). Human activities, such as accidental release and road construction, have also assisted their dispersal by providing pathways and warmer surfaces.
Coexisting with Armadillos
If you spot an armadillo, observe it from a distance and avoid direct interaction. Armadillos are shy creatures that flee when they sense human presence. The Illinois Department of Natural Resources encourages reporting sightings, especially in central and northern counties, to help track their expansion.
Armadillos are natural diggers, and their foraging habits can lead to property concerns. They use strong claws to unearth insects and grubs, leaving numerous small, shallow holes, a few inches deep, in lawns and gardens. They also construct burrows, which can be up to 8 feet deep and 25 feet long, potentially undermining foundations, driveways, or other structures.
Regarding health considerations, armadillos are known carriers of Mycobacterium leprae, the bacterium causing leprosy (Hansen’s disease). While armadillos are one of the few mammals that can carry this bacterium, the risk of transmission to humans is low. Infection requires prolonged, direct contact, such as handling the animals or consuming improperly cooked meat. Most people (around 95%) are naturally immune, and current testing of armadillo specimens in Illinois has not detected the presence of Mycobacterium leprae. Still, it is always a good practice to avoid handling any wild animals to minimize potential exposure to various pathogens.