Bat Information and Control

Bats are the only flying mammal in the world and can eat over 500 flying insect per hour all night long. Like other mammals, a very small percentage of bats contact rabies. Exposure to the rabies virus is remote if contact with bats is avoided and pets are properly vaccinated. Bats are nocturnal (active at night) and roost in the daytime. Although a few species will enter buildings to roost, normally they are not found in buildings. Little brown bats commonly invade structures in the spring and summer, while big brown bats use buildings year-round for raising young and hibernation.

Most bat complaints occur in July and August when bats enter houses via overhangs, eaves, unscreened vents, and construction gaps. Bats can squeeze through holes 3/8” wide (the size of a dime). They occasionally enter houses through chimneys and open windows and may get lost in the building interior. Individual bats that get into a home can often be let out by opening the doors and windows. Exclusion is the main priority in bat control. Elimination of all structure holes of ¼”, especially in the top portion of the building is a priority.

photo of bat

All Illinois bats are protected under Wildlife Code (17 ILL ADM. CH.I, SEC. 525). Bats cannot be shot, trapped, poisoned, transported, or held in confinement except when a bat is found in an area where contact with humans or domestic pets may occur. Repellents are generally ineffective against bats and may even cause bats to move further into a building. Bats flying outside at night pose little threat to humans. A bat that is active during the day, moving on the ground, or found in a place where bats are typically not seen, should be avoided. Never purposely touch a bat.

If a bat is in your home:

Try and isolate the bat to a room with outdoor access. Remove any people and pets in the room/area, especially babies and sleeping people. Put towels or blankets under the room door. If you are not able to restrict the bat to a room, you can attempt trapping the bat in a box and slide cardboard underneath it or capture it in a blanket. Wear leather gloves to handle the bat. NEVER touch the bat with bare hands. If you do not feel comfortable capturing the bat, contact the municipality police department or county animal control department for assistance. If a human or pet has been bitten, the county health department will need to be notified to assess the rabies exposure risk. DO NOT release the bat until you have spoken to the local health department.

If a bat is on the ground:

A bat on the ground is likely sick or injured or a juvenile learning to fly. Unless children or pets are in the area, DO NOT attempt to pick up a grounded bat. If the bat needs to be moved, wear leather gloves, place a container over the bat and slide a piece of cardboard underneath it. If the bat bit a human or pet, keep the bat for rabies testing and call the local Health Department or Animal Control Department. If the bat did not come in contact with humans or pets, release the bat at the base of a tree. If the bat is healthy, it will gain its bearings and crawl up the tree.

Information on Bat Encounters
Living with wildlife – Illinois DNR
Wildlife Illinois - Bats
CDC – Bat Information