Little Brown Bats (left two photos) and Big Brown Bats (right photo) roosting in the rafters of old buildings
Have you seen bats in or near your home?
Bats provide a tremendous benefit by helping control insect populations. These include a variety of agricultural and forestry pests, as well as several species of biting insects. Many bats love to roost in human structures and these sites may be important resources for bats in your area. One bat species that commonly occupies buildings in Alberta, the Little Brown Bat, is listed under the Species at Risk Act as Endangered. Providing bat habitat and avoiding unnecessary destruction of bat colonies has never been more important.
Bats don’t build nests and instead rely on already existing structures in their environment. They prefer to avoid human contact altogether, and if roosting in buildings, typically use areas where humans do not enter, such as attics, rafters, under siding, and the hay lofts of barns. Of course, some bats do get lost and may need to be safely removed from your home. Bats don’t gnaw like rodents, so they won’t chew wiring or insulation. However, they may deposit large volumes of guano, which can make them unpopular among property owners.
If allowing bats to occupy your property is not an acceptable option, please see the instructions below for how to safely and humanely remove bats. Consider installing a bat house before evicting bats to offer an alternative place to live. Larger bat houses with multiple chambers should be selected, because these are better able to support maternity colonies.
Bat pups cannot fly and are typically left behind while their mother forages for insects at night. They will die if their mother is excluded from re-entering their roost during the reproductive period (June – August). Eviction during the spring prior to pups being born may still result in lower reproductive success of the colony. The best time to complete structural repairs is during the winter (October to February), when most bats leave to hibernate. However, big brown bats may hibernate in buildings that are prevented from freezing (typically heated buildings), so care should be taken to ensure that bats will not be trapped inside.
See these links for more information on managing bats in your home