Scritch, scritch, scritch. Shuffle, shuffle, shuffle.
When those muffled noises came from the eaves above my pillow again this spring, I knew one thing for sure.
They’re back.
Some folks rent basements or spare bedrooms to tourists and other sojourners. Off and on for the better part of a decade, the space above the master bedroom of our family’s two-story house has been an Airbnb unit for other kinds of seasonal visitors — and we’ve been their superhosts.
Bats.
There was the November night in 2014 when I caught a glimpse of one swooping through the living room. Then there was the summer evening a few years later when my husband and I did a front-yard stakeout and counted one, two, 40, and soon 49 bats as they flew out of the eaves at dusk.
Ever since, we’ve been wondering how to coexist with these mysterious nocturnal creatures.
We know they’re our fellow mammals, “the only true flying mammal that we have in the world,” Missouri Department of Conservation Bat Ecologist Jordan Meyer said. We know bats bring benefits, too, because mosquitoes have been the last thing on our minds on warm nights on the deck when we’ve marveled at their natural predators crisscrossing the sky.
We’ve also been aware that a bat bite could potentially carry rabies — and that a little bit of guano goes a long way. So before the COVID-19 pandemic, we thought it best to send our summer houseguests on their way.
A little Google research had my husband climbing an extension ladder at sunset to screen the bats out of their five-star vacation spot. It worked, kind of like changing a lock after the tenants have gone out for a leisurely meal.
Until a few months ago, when I heard those now-familiar roosting sounds from the other side of the ceiling — a little too close for comfort — and thought, Here we go again.
My guess is that the same early spring storm that uprooted a tree here also ripped the screen exit door from the bats’ old home away from home.
And this time, when the bats came back, so did another question:
How on Earth can we coexist?
The answer, of course, is that we already do.
In Missouri, home to 14 kinds of bats, big brown bats (Eptesicus fuscus) are the species most likely to seek shelter in human-made structures.
“They’re common,” Meyer said, noting that big brown bats aren’t endangered like some other species. ”We find them everywhere.”
That scritching and shuffling I heard may have come from bats settling into either a maternity or bachelor colony. Meyer explained spring is when male bats fly off while females roost together to give birth to pups and nurse them.
By early to mid-July, big brown bat pups learn to fly on their own, he said. In August, as colonies scatter, bats also begin to show up on porches, patios, shutters and siding.
“In the next month or so, I usually get calls about people finding bats in places where they’ve never seen them before,” Meyer said. “That’s usually juveniles trying to find a place to roost.
“Just like teenagers, they don’t know where it’s a bad place to go.”
I’m pretty sure I shrieked one evening when I spotted a bat almost perfectly centered in the oval window under the ceiling beam in our bedroom, like some early and oh-so-authentic Halloween decoration. I’ll never forget the sight of my husband wearing leather work gloves and coveralls as he brandished a fishing net duct-taped to an extension pole — all to capture that intruder and get it out of the house.
Had it squeezed in through a skinny gap between a window and a screen?
An opening the size of a quarter is a large enough point of entry for most bats, Missouri Department of Conservation Natural History Biologist Rhonda Rimer said.
“Think about chimneys, air vents, where plumbing enters the home, power lines,” Rimer said. “There’s a lot of options for them to get in.”
Remember, bats are small.
“A good-sized big brown bat weighs about 20 grams,” Meyer said. “They’re still tiny, even though they’re one of our largest species.”
Should they stay or should they go?
Even one of these tiny creatures, though, seems to have a larger than life ability to rouse a fight-or-flight response when they find their way into human roosts.
“A lot of folks see them in the house and are inclined to violence,” Meyer said.
I gasped, anyway, to walk into the kitchen one morning not long after our 2014 sighting and see one hiding under an antique trunk.
Yet if a bat gets into your house, Meyer said, also remember, “they’re definitely more intimidated by you than you are by them.”
Don’t handle or grab one without wearing gloves, he said, and wait until it has settled down to trap it under a can or jar, then release it outdoors. The “A Bat in the House” section of the department’s page on bat control explains this process.
Irrational fears aside, there are reasons humans and bats shouldn’t live within the same four walls.
While bats get a bad rap for being rabies carriers — skunks, for example, are more likely than bats to transmit rabies, Meyer said, it’s also true that the detection rate for the disease is higher among bats than other animals. He advises people to call their county health department if they or a pet has been bitten or scratched by a bat.
In addition, he said, exposure to a large amount of bat waste, or guano, in a confined space like a hot attic can put humans at risk for the lung disease histoplasmosis, especially if they don’t follow safety precautions to remove it.
“If someone has a large amount of bats in their attic, if they’re going up there to clean it out or to screen out the area after the bats have left, then I tell people to wear an N95 (respirator) mask,” Meyer said.
Get the guano gone-o
While guano may make the perfect carpet for a bat colony, an accumulation of it can also weaken human habitats, Rimer said. That’s why guano is a major cause for concern.
“If they’re in an attic situation, (bats) can compromise the structure of the house eventually,” Rimer said. “That’s not super common. They usually have to have been around quite a while.”
Sometimes, property owners don’t realize how much damage guano has done, said Crystal Chapman, owner of Southwest Nuisance Wildlife Control, a licensed and insured wildlife control and removal service in Springfield.
Even when Chapman discovers something like disintegrating, rusted aluminum soffit ruined by bat droppings and urine — and even when guano is piled a foot high and she has to remove insulation in an attic to get it clean.
“I’ve been in bat guano up to my knees,” Chapman said.
Customers also sometimes don’t understand why she can’t always clean up those messes on demand. From spring through early fall, when mothers and their pups are nesting, the best she can do is give customers a “game plan” for excluding and cleaning up after the bats after they’ve left the roost, she said.
“You just kind of have to wait until the first of September,” Chapman said. “If you exclude all those moms, then their babies will pass away, and that’s not what we want to do.”
Don’t kill bats; it’s the law
Killing bats is not what homeowners want to do, either. They’re protected under the Wildlife Code of Missouri, and fumigating, repelling, trapping or shooting bats aren’t safe or practical options for removing them, according to the Department of Conservation.
However, excluding bats from structures is a humane solution, especially after nighttime temperatures drop to 50 degrees and below, and bats start to migrate to caves for the winter, Meyer said.
First, make sure all the bats have flown out of a building.
“I tell people to stand outside 15 minutes before sunset and watch bats come out,” Meyer said.
Next, Meyer said, place a one-foot-square piece of heavy cloth like denim or canvas or wire mesh (without sharp edges) over the roost’s entrance, fastening only the top of the cloth or mesh to the structure. Plastic bird netting is an option, too, University Extension guidelines for homeowners say.
“If you put that over the hole and secure the top of that, the bats are able to push their way out of the hole and fly away,” Meyer said. “Just having that flap there will cause them to leave and not come back in.”
On the other hand, if a lone bat perched outside isn’t causing a problem, Meyer advises to “just give it some space and give it some time. Most of the time, just being near a bat is enough disturbance for the bat to not go back to that spot.”
Bats are shy and “very secretive,” he added. “They don’t like to be noticed by a predator.”
The benefits of bats
People who enjoy noticing bats take a live-and-let-live approach to these seasonal squatters.
“Some people have made a decision that, ‘Hey, they’re on my front porch. I don’t need to use that door in the summer,’” Rimer said.
“It makes me very happy,” she added. “It is inconvenient for them, but it is very interesting for them because they get to see the flightless young.”
Ben Caruthers and his wife, Jodi, often sit on the patio of their home near McDaniel Lake to watch the night flight of the bats.
“It’s amazing to watch them, really,” said Caruthers, vice president of the Greater Ozarks Audubon Society. “They’re graceful in the movements they make across the sky; it’s not like a bird flight.”
Using echolocation, bats emit high frequencies to navigate toward prey and away from predators and obstacles, Meyer said.
“A lot of people will watch bats when they fly and think they’re flying very random and erratically, but really what they’re doing is interpreting their situation,” Meyer said.
As insectivores, their appetite for bugs–including mosquitoes–is another reason some are happy to have bats around. They’re “just voracious eaters,” Meyer said.
“In summertime, a pregnant female bat will eat even twice her body weight,” he said. “Essentially, bats perform a natural pesticide service and can save us and farmers a multitude of money.”
Making a bat house
In hopes of encouraging bats to roost nearby — but not under the rafters — some Missourians erect bat houses on their property. Bat houses, about the size of large birdhouses, only with narrow slots for entrances, can be purchased, and Bat Conservation International and University of Missouri Extension offer free building plans.
Paint a bat house gray so it won’t get cold or too hot in the sunshine, Meyer said, and place it 10 to 15 feet off the ground. Clear the area underneath, and minimize pesticide or insecticide use, too.
“Sometimes, bats will use it right away,” Meyer said. Bats may also “layover” in bat houses during their fall migrations.
While bats have roosted in the breezeway and carport at the Caruthers house, Ben Caruthers said he isn’t sure whether they’ve used the bat house he attached to a garage four or five years ago.
According to Rimer, bats will go where they will–and if an attic provides prime conditions, that’s where they’ll head.
“People hope the bat houses will draw bats away,” Rimer said. “I just try to adjust people’s expectations. They may use them, they may not.”
Bats know what they like, she said.
For me, at least, trying to understand the elusive nature of our on-again, off-again houseguests had me almost missing them four years ago as I watched them glide across the dawn sky to a different shelter.
“Day sleepers, put out your signs,” I journaled. “You used to shuffle around in our eaves / Slip in through cracks, gaps in screens, doors not quite shut.”
This spring, I learned they weren’t gone for good. And now, as summer ends and it has been weeks since I’ve heard their scritching and shuffling, I wonder:
When will they be back?
Bats are still a mystery to me. Yet after having them around here and there for several years, I think I understand them a little more than I once did.
“I think bats provide an excellent service, and just like with any wildlife, it’s always good to appreciate them from a distance,” Meyer said. “Do your best to provide for them because they’ll provide for you.”
