Time's short to shoo any unwanted bat guests

Bats are settling in for maternity season right now anywhere they can: Churches, homes, bat houses and anywhere else that suits them as a place to raise their pups.

Though these furry, flying creatures are a benefit to the environment, they might not be the best roommates.

“During bat maternity season, bats gather to give birth and raise their young. Some bat species form maternity colonies in which female bats raise their young alongside numerous other bats of the same species,” said Carli Segelson, a Florida Fish and Wildlife Conservation Commission spokeswoman. “The number of bats in a maternity colony in Florida can range from fewer than 10 individuals to several hundred thousand.”

State wildlife officials are reminding residents that if you believe you may have bats trying to nest, you’d better shoo them while you can.

That’s because the state’s 13 bat species are protected by Florida law during maternity season, from April 15 until Aug. 15. It is illegal to exclude bats from their roosts during this period when bat pups aren’t able to fly or feed themselves. If bats have taken up residence in buildings or other structures, they must be allowed to stay until Aug. 16.

“If you can exclude them at the appropriate time of the year, it can help them out and help you out,” said Verity Mathis, mammal collections manager at the Florida Museum of Natural History.

Safely excluding bats from a home or building can be time-consuming (it takes at least four days), which is why many people hire professionals, but if residents take the time and do it correctly, the bats will willingly leave the structure and not return. The FWC has directions for safe exclusions on its website, as well as a Youtube tutorial.

There are multiple pest control companies in Gainesville that handle bat exclusions. Rachael Drotar, manager at Centurian Wildlife Control, said her agency tends to get a spike in bat cases right before maternity season. She said sanitizing the roost area after a bat exclusion is key to making sure the bats don’t come back.

Though bats may seem like pests, they are more like pest control. They are adaptable creatures that can roost almost anywhere and eat their weight in insects, Mathis said. In an agricultural state such as Florida, their ecological benefit as a natural insecticide is invaluable. The FWC has estimated that bats have saved billions of dollars for the agriculture industry.

“Throughout the world, bats provide many ecological services such as pollination, seed dispersal and insect removal. In the U.S., bats play a vital role in insect control such as reduction of harmful agriculture pests and those that spread disease,” Segelson said.

According to the FWC, building bat houses is one way to promote bat conservation while also encouraging them to stay out of other structures. Mathis said the houses give bats a “protected habitat to roost and to colonize in their natural behavior.” The University of Florida’s bat houses are home to approximately 400,000 bats that can eat over one ton of insects per night.

Holly Ober, a UF associate wildlife ecology professor and bat expert, said residents are more likely to see bats right before maternity season and right after.

Currently, female bats are preparing for maternity season by consuming as many insects as possible. After maternity season, populations will approximately double, potentially causing a spike in sightings.

To learn more about bats and bat exclusions, visit myfwc.com/bats. To learn about Gainesville’s bat houses and bat emergence times visit floridamuseum.ufl.edu/bats/

How to get bats to leave:

If you think the bats are roosting somewhere accessible, such as an attic, go up during the day and check. If they are roosting somewhere inaccessible, you can listen for them, watch them emerge at sunset or check the building’s exterior for brown smudges caused bats’ natural body oil.

If you do have them, find out where they’re coming from. Search for the crevice the bats are using to enter. Bats can fit into crevices as small as the width of your thumb, so be vigilant.

To exclude the bats, use mesh netting or a tube to cover the entrance. If using netting, fasten the netting on the top and the side, but not the bottom, so the bats drop under the netting. The bats will be able to drop under the netting and leave but won’t be able to figure out how to get back in. If using tubing, the bats will fly out of the tube, but won’t be able to crawl back up. The FWC has multiple different suggestions for the type of netting and tubes to use.

Seal any other crevices bats might be able to get into. They can fit into any crevice as wide as your thumb.

Wait. The bats will evict themselves, usually over a period of about four days. Leave the tube or netting up for the entire four days, and when the bats have been successfully excluded, take it down and seal the hole. 

Important tips:

Bat exclusions must be performed outside of bat maternity season

Bat exclusions must be performed when there are four consecutive days with temperatures above 50 degrees and there is no inclement weather.

Leave the netting or the tubing up for four complete days. That will ensure every bat leaves.

Do not trust pest control professionals who exclude bats during prohibited times or use disproven or illegal methods.