But on a prairie, they are a source of life and vitality.
Scientists at Chicago's Lincoln Park Zoo are raising meadow jumping mice and releasing them into the wild to help restore dwindling Midwestern prairies.
Right now, biologists there say only 1 percent of historical prairie grasslands remain in Illinois.
So the zoo is raising the mice and other species to help bring back restored prairies, including some at the Lake County Forest Preserves north of Chicago.
Once the mice reach adulthood, researchers anesthetize them and attach tiny radio collars so they can track their movements in the natural habitat, according to Allison Sacerdote-Velat, a reintroduction biologist at the zoo.
She and other scientists released several mice in late July at the Rollins Savanna forest preserve in Lake County. They hope the mice will mate and distribute the grassland seeds they eat to help spread the plant life.
"We need to restore certain wildlife species in order to keep the ecosystem functioning," she says.
She says trackers will likely find that some mice will end up as food for owls, coyotes and other predators.
But that's as it should be. "It's all part of the cycle," Sacerdote-Velat says.
Here's a gallery of images by photographer Scott Eisen of the mice getting radio collars at the zoo and their release in Lake County, north of Chicago.