Moles are active, yet mostly unseen, subterranean mammals known for their extensive tunneling systems in Illinois. Their presence is easily confirmed by the distinct trails and mounds of soil that appear in lawns and gardens across the state. Understanding the species responsible and the signs they leave behind is the first step in recognizing their impact on the landscape.
Moles Found in Illinois
The most prevalent mole species found throughout Illinois is the Eastern Mole (Scalopus aquaticus). While the Star-nosed Mole (Condylura cristata) is technically present, it is considered very rare, making the Eastern Mole the primary concern for most residents. This small mammal is uniquely adapted for its life spent almost entirely underground, possessing a robust, streamlined body that ranges from 5.5 to 8 inches in length.
The mole’s most distinguishing feature is its pair of massive, paddle-like front feet, equipped with large claws and pointing outward, functioning as powerful shovels for excavation. Its fur is a velvety charcoal gray that offers no resistance, allowing the animal to move effortlessly through its tunnels. The eyes and external ears are not visible, covered by skin and fur, reflecting the mole’s limited reliance on sight. Instead, the mole uses its elongated, hairless snout to sense its surroundings and locate food.
Identifying Mole Activity
The presence of a mole is almost exclusively indicated by the visible disturbances it creates on the surface of the ground as it tunnels. These signs manifest in two distinct forms that provide clues about the animal’s current behavior.
The first is the surface runway, which appears as a narrow, squiggly, raised ridge of soil or turf that is easily compressed underfoot. These shallow tunnels are typically just beneath the grass roots and are the mole’s primary hunting paths, used once or repeatedly while searching for prey.
The second type of evidence is the molehill, a small, conical pile of loose, excavated soil that resembles a miniature volcano. These mounds are created when the mole digs deeper, more permanent tunnels for nesting, resting, or travel. The soil pushed out from these deeper tunnels (6 to 10 inches below the surface) forms the characteristic volcano shape, often with the entrance hole located in the center.
Preferred Habitats and Diet
The constant tunneling behavior is directly linked to the Eastern Mole’s specialized diet and its requirement for specific soil conditions. Moles are insectivores, and their diet consists mainly of earthworms, insect larvae, and grubs, which they must consume in large quantities to sustain their high metabolic rate. An individual mole must eat between 70% and 100% of its body weight every single day to maintain the energy needed for continuous burrowing.
Moles prefer environments with moist, loose soil, such as sandy or loamy compositions, which are easier to excavate and support higher populations of invertebrate prey. They actively avoid heavy clay, rocky ground, or overly wet areas because these soils are difficult to maneuver through and do not provide good foraging conditions.
The constant tunneling, which can involve digging up to 18 feet of new burrow in a single hour, is a foraging strategy. Because of their need for food, they are active year-round, moving deeper underground to stay below the frost line during winter months.