Fall Is A Good Time To Safely and Humanely Evict Bats - Wisconsin DNR

Sunday, September 5th, 2021 -- 6:43 AM

With bats soon leaving their summer roosts to return to their winter hibernation sites, the Wisconsin Department of Natural Resources reminds Wisconsinites that fall is a good time to safely and humanely evict bats from homes and buildings.

Now through May 31st, before the nursing and baby bat protection period begins, you can keep bats out of homes and buildings by following best practices. The DNR provides do-it-yourself instructions and information on hiring a professional to get bats out of buildings humanely through a process called exclusion. Exclusion includes sealing a building except for primary exits, outfitted with one-way doors that let bats exit and prevent re-entry. Exclusions are prohibited June 1 through Aug. 15 to protect Wisconsin’s little brown and big brown bats during their maternity seasons. Exclusions occurring during this period will separate mothers from their flightless pups, leaving the pups to die of starvation and potentially exacerbating the homeowners’ bat problem as frantic bat mothers search for an opening to reach their pups.

Effective exclusion efforts should target time periods in the fall and spring where temperatures are consistently above 50°F as bats are generally active at temperatures above that level. To permanently and humanely evict bats from structures, one-way venting devices should be installed at the primary entries/exits for 7-10 days in addition to sealing up secondary holes, cracks and crevices that may allow entry into a structure. Primary entries should be closed after a one-way venting device has been in place for 7-10 days and bats are out of the building.

Feel free to contact us with questions and/or comments.