Typically, fifteen species of bats (Order Chiroptera) can be found in Missouri. Some occur statewide and some only regionally. A number are year-round residents but others are here seasonally. These beneficial mammals consume tons of insects daily and some act as plant pollinators. Conflicts can occur when bats take up residence — sometimes in large numbers — in the attics of homes and other buildings where the accumulation of urine and feces can endanger human health.
All bats are protected by the provisions of the Wildlife Code of Missouri. Although the Code allows landowners to take action when wildlife is damaging property (see 3 CSR 10-4.130 Owner May Protect Property; Public Safety), nine bat species are listed as species of conservation concern, and three are classified as state endangered. Consequently, please exercise caution when addressing bat-related problems.
A bat in the house. An individual bat may accidentally enter your home through an open door or window or drop down a chimney. If this occurs, wait until the bat settles, then cover it with a can or jar. Without touching the bat, tip the container slightly and slide a magazine or piece of cardboard between the can and wall, forcing the bat into the container. Wearing gloves during this procedure is recommended. Release the bat unharmed outdoors.
Exclusion. Bats can gain entry through surprisingly small openings. Use caulk to seal cracks, crevices, and holes. Repair or replace damaged siding, trim, and molding. Cover larger openings such as vents and louvers with quarter-inch hardware cloth. Install a chimney cap to exclude bats and other animals. Repairs should be made only when bats are absent.
If bats are already present, watch the outside of the building during the last half-hour of daylight and note where they emerge. Especially note such places as attic louvers, jointure of chimney and house, and gable ends. The next day, tack a 12-inch-square piece of denim or other heavy cloth over each opening (tack only along the top edge). That evening the bats will push their way under the cloth to exit but will be unable to locate the opening when they return. Wait two to three days to ensure that all bats have vacated and then make repairs. Young may be present during May, June, or July (varies by species), so delay any action until they can exit with the adults.
In some instances bright lights can evict bats from a roost area. It may be necessary to illuminate the area for several days before all the bats leave.
Fumigants/repellents. Not recommended. None are known to be effective. Mothballs contain toxic naphthalene and the vapor is harmful to humans.
Trapping. Not a practical option.
Shooting. Not a practical option.
In case of a bat bite. Like all mammals, bats can contract rabies, but the risk of their infecting humans is slight. As a precaution against disease, do not handle a live bat. If you are bitten by a bat, wash the area immediately with hot soapy water and contact a physician. If possible, capture the bat without damaging the head (wear heavy leather gloves or scoop it up with a shovel) and place it in a jar or plastic bag and refrigerate so it can be tested by health officials.
For additional information on these and other species, see the Internet Center for Wildlife Damage Management listed under External Links below.