White-footed mice show up in Illinois records more often than most small mammals in this batch, and the state’s conservation rank matches that picture: NatureServe lists it S5, Secure, the healthiest rating on the scale. With 951 records logged statewide, it’s among the better documented rodents here, though that count still reflects where people set traps or cameras more than any true population size.
Records come from Fermilab Natural Areas along with Cook County forest preserves and Midewin National Tallgrass Prairie, a spread that tracks the brushy understory and log piles this mouse favors for cover. Large dark eyes, a white belly, and a sharply bicolored tail set it apart from the introduced house mouse it sometimes shares a building with.
Reports climb steeply through spring and peak in June, more than double the count of any other month, before tapering into fall. Warmer nights likely mean more people are out looking, and a nocturnal mouse becomes easier to notice once trail cameras and evening hikers are active again.
Full species profile
