Many commercial bat houses are not suitable for bats because of inadequate design or construction, or they lack prope...
Bats in Buildings
Excluding Bats From Buildings
Excluding Bats From Buildings
An important note about bat exclusion in the U.S. and internationally:
Legal issues about bats and bat exclusion vary widely around the globe.
“In Britain all bat species and their roosts are legally protected, by both domestic and international legislation.
This means you will be committing a criminal offence if you:
- Deliberately capture, injure or kill a bat
- Intentionally or recklessly disturb a bat in its roost or deliberately disturb a group of bats
- Damage or destroy a bat roosting place (even if bats are not occupying the roost at the time)
- Possess or advertise/sell/exchange a bat (dead or alive) or any part of a bat
- Intentionally or recklessly obstruct access to a bat roost”
We admire and respect the bat groups in the UK and other European countries which have done such wonderful work protecting bats, and we often refer people to the Bat Conservation Trust website, which contains a treasure-trove of excellent information.
In the United States, bats roosting in buildings is one of the most common issues brought to BCI. While we always discuss the option of doing nothing if bats are roosting in an area of a home or public building where they will not come into contact with humans, many people are not comfortable leaving the bats alone. Since laws about bats are different in every state (if they exist at all), and federal laws generally protect only bats on the endangered species list, proper exclusion of bats (along with proper education ABOUT bats) is sometimes the only way to save them. The key phrase is “proper exclusion;” we rarely recommend the “do-it-yourself” approach to exclusion. Instead, we hope that people armed with proper information will do the right thing - for example, not hire an exclusion professional who seems focused on the “dangers” of bats, refers to bats as “vermin” or “pests” or agrees to exclude bats during the summer when pups may be present.
We also work hard to educate the public about the importance of replacing lost roosts in buildings as an integral part of the exclusion process.
BCI is devoted to conservation, education, and research initiatives involving bats and the ecosystems they serve. We hope that a time will come when bats are more widely protected here in the U.S. and internationally, and that one day excluding bats from buildings will not be necessary.
Why Do Some Bats Roost in Buildings?
Over time, human disturbance of natural roosts in trees and caves has resulted in the loss of important bat habitat, and bats have adapted to human structures because they give bats what they need—stable, warm temperatures, microclimate options, protection from predators and replacement roosts. Some people are tolerant of bats roosting in their attics or in other parts of their homes, as long as the bats are not appearing in living spaces and sharing space with humans.
On occasion, a solitary bat may accidentally fly into a home, garage or other building through an open door or window. Such incidents often involve lost youngsters whose primary goal is a safe escape. These bats will often leave on their own if a window or door to the outside is opened while others leading to the rest of the building are closed. Bats are rarely aggressive, even when chased, but may bite in self-defense if grabbed. As with all wild animals, bats should never be handled with bare hands. If you are sure no human exposure has occurred, the bat’s exit can be hastened by waiting until it lands, and then covering it with a small box or other container, gently slipping a piece of cardboard under the bat and over the opening, and releasing the bat outside (preferably near dark). Keep doors and windows to these buildings closed, and window screens in good repair to prevent bats from re-entering.
Excluding Bats from Buildings and Installing Bat Houses
There may be little reason to evict bats from areas where they don’t come into contact with humans, but when exclusion is the best option, it’s important to fully understand the process and not cut corners. It is also essential in scenarios involving large numbers of bats being displaced to install one or more bat houses as replacement roosts. Bat houses should be installed as far in advance of the exclusion date as possible—weeks or even months ahead, and should be within the flight path of emerging bats. Keeping bats in the vicinity of their former roost allows people to continue to take advantage of their pest suppression services, and may prevent bats from simply moving into another building.
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