Armadillos are present in Illinois. While these armored mammals were once strictly associated with the southern United States, they have established a presence in the state over the past several decades. This northern movement is part of a larger trend of range expansion that wildlife biologists are actively monitoring.
The Species Expanding North
The species making its way into the Midwest is the Nine-banded Armadillo, Dasypus novemcinctus. Historically, this mammal’s range began in Central and South America before it expanded into the Southwestern United States in the mid-19th century, particularly through Texas and Mexico. The northward migration into 14 additional U.S. states is attributed to several factors.
One of the primary drivers of this expansion is a change in climate, specifically milder winters that reduce the number of days the ground remains frozen. Armadillos have a low metabolic rate and poor fat reserves, which makes them highly susceptible to cold temperatures. They cannot survive when they cannot access their primary food source—subsurface invertebrates—for more than a few days. Human-induced landscape changes also facilitate this movement, as they utilize forested river corridors and warm road edges as dispersal routes. Studies in southern Illinois show armadillo occurrences increase near major roads, which act as thermal refugia by trapping heat during colder conditions.
Where Armadillos Are Found in Illinois
Armadillo populations are concentrated in the southern and central portions of the state, where breeding has been documented. The animals arrived in southern Illinois as early as the 1970s, and their numbers have increased significantly since the early 2000s, with a more than 30-fold increase in their presence in newly colonized areas. The most robust populations are found in the 16 southernmost counties, particularly along the heavily forested areas near the Mississippi and Ohio Rivers.
The northern spread of the armadillo is primarily limited by the depth and duration of snow cover and ground frost. Because they must dig for their food, prolonged periods of frozen soil prevent them from feeding and can lead to starvation. Biologists suggest their northern limit is currently near the 40th parallel, which runs roughly through the area of Champaign County. Pioneering individuals are often sighted much farther north, and the Illinois Department of Natural Resources is actively tracking reports in central and northern counties, including Tazewell, Champaign, and Will counties, to monitor this ongoing expansion.
Interacting with Armadillos
The most common interaction residents have with armadillos involves their digging. Armadillos forage by rooting through soil, lawns, and gardens in search of insects, grubs, and other invertebrates, often creating numerous shallow, cone-shaped holes. This nocturnal behavior can cause significant damage to landscaping, leading to calls for nuisance wildlife removal.
Armadillos can carry the bacterium Mycobacterium leprae, which causes Hansen’s disease (leprosy) in humans. The risk of transmission in Illinois is very low, and there have been no confirmed cases of infection linked to armadillos within the state. In the southern U.S., where the disease is more prevalent in armadillos, transmission typically occurs only through extensive, direct contact, such as frequent handling or consumption of the meat. Wildlife experts advise residents to observe armadillos from a distance and avoid touching them or their burrows.