The 2010s were a tough decade for bats in Maine and across much of the United States and Canada as a disease called white-nose syndrome spread quickly, decimating populations as it went.

First identified in Maine in Oxford County in 2010 or 2011, the syndrome led to an estimated 97% decline in the number of bats here: A survey that counted 790 bats in 2010 found just 27 by 2016.

“There’s a long, sad list of species that have been affected or damaged by disease like this,” Erik Blomberg, a professor at the University of Maine, said in 2019. “But this is pretty unprecedented.”

However, if you think you’re seeing more bats around your house or barn, you’re probably not mistaken.

Not only is this the time of year when bats are usually out and about, according to Corey Stearns, a biologist with the Maine Department of Inland Fisheries and Wildlife, but bat populations have been rebounding in recent years as well, bringing back a species that was as much a part of Maine summer nights as peepers and lightning bugs.

Why am I seeing so many bats right now?

A big part of it is life cycle, Stearns said.

“This is the time of year when the bats that were born this year are starting to fly around,” Stearns said. “And just like our kids, they get into places where they shouldn’t be.”

If you’re seeing the bats around a building, it’s probably a big brown bat or little brown bat because they like to roost in structures, Stearns said.

They were historically a common sight in Maine until white-nose syndrome hit, causing an almost instant decline.

So what happened to white-nose syndrome?

Nothing, really.

The fungus that causes the disease is still prevalent in the cool, damp caves where many bat species like to hibernate. From there, it can spread from bat to bat and cave to cave, afflicting the animals with skin issues that cause it to wake up from hibernation, forcing them to use up their winter fat stores. If that happens, they may starve before spring.

However, Stearns said, it appears that bats are adapting here in the Northeast, moving to colder areas of the caves where the fungus can’t thrive, and where they can get the rest they desperately need.

“It’s causing a bit of a rebound,” Stearns said.

Nationally, there is some cause for optimism when it comes to fighting the syndrome. “I really feel like we’re starting to see some signs of recovery finally,” Greg Turner, a wildlife biologist at the Pennsylvania Game Commission, told the New York Times last year. “I feel much more comfortable than I used to feel, that’s for sure.”

But populations still pale in comparison to the time before the syndrome took hold, and the fungus remains an enormous challenge for wildlife experts to overcome.

What do I do if I encounter a bat?

If you find a bat in your house, and no person or animal has been exposed to it, then try to let it go free.

“In a house, the best advice is to close interior doors and open exterior doors,” Stearns said. With any luck, the bat will just fly away.

However, if it’s possible that a person or animal has been bitten or scratched by a bat, then the bat should be tested for rabies.

Rabies is not very common in bats, Stearns said, but you shouldn’t take any chances. If you wake up with a bat in the room, or find a bat in a room with a child or near a pet or livestock, then try to safely capture it.

“They do carry rabies and other diseases, so you should not handle them with bare hands,” Stearns said.

According to the Maine Center for Disease Control and Prevention, once a bat is captured — using thick gloves and a container to protect yourself — you can contact the Maine Warden Service or local animal control to have it tested.

If someone has been bitten or scratched, they should wash the wound thoroughly and seek medical care, the CDC said.

Human rabies cases are rare in the United States, and Maine last reported a human rabies case in 1937, the CDC said. In 2024, bats made up 43% of the 667 animals tested by the Maine CDC and 10 bats tested positive for rabies.

In fact, far from scary, it’s good to have bats around, Stearns said.

First and foremost, bats are prodigious eaters of insects. Not only does that make our backyards more comfortable for summer nights outside, it saves industries like lumber and farming billions of dollars a year, according to the U.S. Geological Survey.

There are other effects. A recent study found that farmers used more pesticides as bat populations fell, ultimately causing a higher rate of infant mortality as the amount of toxic chemicals in the environment increased.

Bats are also pollinators and relied on by more than 300 fruit species. They also spread seeds for nuts, figs and cacao.

Yes, without bats, there would be no chocolate — or at least it would be a lot harder to come by.