Little brown bats roosting in an attic. / Photo Credit: Wisconsin DNR
” data-medium-file=”https://www.thefarmwi.com/wp-content/uploads/2025/10/bats-300×225-1.jpg” data-large-file=”https://www.thefarmwi.com/wp-content/uploads/2025/10/bats.jpg”>
Pictured: Little brown bats roosting in an attic. Photo credit: Wisconsin DNR
It’s International Bat Week! As a group of mammals, bats are unique. They’re also extremely important members of the natural world, says the Wisconsin DNR.
Bats are vital to many ecosystems and provide significant environmental, economic, and public health benefits. For example, bug-eating bats consume large numbers of agricultural pests, saving farmers and forest owners billions of dollars every year.
Of the eight bat species found in Wisconsin, four are state-threatened species: the big brown bat, little brown bat, northern long-eared bat (also federally endangered), and tricolored bat. Another, the silver-haired bat, is of special concern, meaning the population is declining and in need of conservation action.
In a previous interview with Mid-West Farm Report, Jennifer Redell, a Cave & Mine Specialist with the Wisconsin DNR, explains why we should keep bats around, and what to do if one of these winged friends makes its way into your home.
The decline of bats in Wisconsin is primarily due to white-nose syndrome, a disease caused by a fungus that attacks the bare skin of bats during hibernation each winter. The disease exhausts their energy stores and leaves them vulnerable to starvation before their insect diet becomes available in the spring.
Fortunately, after experiencing steep declines since 2014, when white-nose syndrome first arrived in Wisconsin, recent Wisconsin Bat Program survey counts show rebounding numbers of little brown bats at some significant roost and hibernation sites across the state.
Despite the recent glimmers of population recovery in little brown bats, there’s still a long way to go. Hibernating bats are still stressed by white-nose syndrome each winter, and species like the tricolored bat and northern long-eared bat have not shown similar signs of recovery.
Attend An Educational Bat Event
There are currently 50 bat events scheduled across 34 counties, and more will be added throughout the month of October. Check BatWeek.org’s events page and search “Wisconsin” to find an event near you!
Tips To Help Backyard Bats
- Build and put up your own bat house.
- Plant native plants that are foundational to a healthy backyard ecosystem.
- Maintain an insecticide and herbicide-free yard. They harm bats through their diet.
- Humanely exclude bats from homes and buildings.
