What to do if you find a bat in your house

SALT LAKE CITY — Though most Utahns probably don’t correlate bats with summer, here’s why you shouldn’t be surprised if you find one in your home this time of year. Utahns may see more bats this time of year because the baby bats (also called pups) are learning to fly and leaving their roost for the first time. Here’s what you should know about bats in Utah and what to do if you encounter them.

There are currently 18 confirmed bat species in Utah, but there may be more. They are the only mammals capable of true flight. Bats are found throughout the state and can be abundant wherever they can find food, shelter and water. The greatest species diversity is in the southern part of Utah.

Utah’s bats feed almost exclusively on insects. When insects aren’t available, like during the winter months, the bats typically either migrate or hibernate (although some species do a combination of both and others stay active year-round). Sometimes they hibernate in caves and mines, and recent research in western states has shown that many small bat species also hibernate in crevices in cliffs. Bats in Utah do not usually hibernate in large groups like they do in many eastern states in the U.S. They typically hibernate either in small groups or by themselves.

Five Utah species primarily migrate, flying south from late August through October and then returning in April and May.

“Encounters with bats seem to spike in September as the migratory species, especially the Mexican-free tailed bat, move around the state,” DWR Mammal Conservation Coordinator Kimberly Hersey said.

If you discover bats roosting in your home, what should you do?

Bats in homes are generally maternity colonies of female bats and their babies. The females typically come out of hibernation and take up residence in a structure to give birth, usually in May or June. They then have their babies and begin to increase their activity to support lactation — this is typically when people begin to notice the bats. The young are also becoming more active and starting to fly, which also draws more attention.

“This time frame is the hardest time of year for dealing with bat nuisance issues,” Hersey said. “Since the young can't fly yet and are reliant on their mother’s milk, preventing the mothers from returning to their roosting spot will kill the babies. Because bats are a protected wildlife species, it’s illegal to kill them.

“I've also seen where poorly timed removals lead to bats in attics suddenly finding their way inside someone’s home because the mothers are trying to reach their young. So, unless there is a human health and safety issue where bats are coming into close contact with residents, we do not permit bat colony removal during this time of year. However, actions to prevent them from getting into the living areas can occur. Although it may be inconvenient, after waiting until the young can fly, you can then safely, humanely and permanently address the problem.”

If you suspect there is a colony of bats in your attic, you will need to contact a local, permitted wildlife nuisance control company for help. The DWR will coordinate with that company to authorize the removal at specific times of the year that won’t harm the pups.

What to do if you discover bats inside your house

Because bats can be carriers of rabies, a deadly virus that can be transmitted to people, you should never handle a bat with your bare hands. And if you have physical contact with a bat, contact your local health department for guidance. If you find a bat inside your home, open a door or window, turn off the lights inside your house and turn on a porch light outside. Leave the room and allow the bat to leave on its own.

If the bat does not make its way outside on its own, you can carefully remove it.

• Wearing heavy leather gloves, place a small box or can over the bat.
• To create a lid, slide a piece of cardboard between the can and the wall or curtain, enclosing the bat inside the container.
• Then take the bat outside and release the bat on a tree or other high object.

Although COVID-19 originated in bats, there is no indication that North American bats have been exposed to the disease. Because of the remote potential for humans to spread the disease to bats, bats captured in a home with a known or suspected COVID-19 case should not be released.

Preventing bats from roosting in your attic

• Cool your attic with fans to make it uncomfortable for bats to take up residence.
• Inspect the outside of the building for openings and gaps in siding, chimneys and roof lines.
• Seal cracks and holes with caulking, hardware cloth, foam rubber, foam sealant, tar paper and chimney caps. Do not do this, however, when bats have pups in May through August. Fall is the best time to seal these openings when bats are vacating roosts.
• You can also use bird netting to place over an opening. Staple it down at the top and the sides, leaving the base open. Bats will be able to drop down the netting to leave, but not reenter the roost. Leave it in place for four to five days or until all the bats have left, then seal the holes.

Find more tips and safety information on the Wild Aware Utah website.