Getty Images
As bug season fades, bat season begins—and if you’ve got an attic or a chimney, these flying critters could become a real issue.
While bats may do you a favor and gobble up those annoying mosquitos that surround your home, they also pose a serious health risk. And an attic infestation can cause thousands of dollars in damage.
Now is the time to seal up entry points, look for signs of infestation, and know what to do if a bat makes its way inside.
Where bats are most active—and how they get inside
Bats are widely seen in warmer, humid climates with bug-heavy summers.
“The Southeast and places like Florida, Georgia, and Alabama are all bat-friendly zones, thanks to their long feeding seasons and mild winters,” says Allan Bossel, pest control expert at Bed Bug Exterminator in Saint Petersburg, FL.
The Midwest and Northeast come next because of their dense trees and large attics. In each of these regions, summer is the trigger season. It’s when maternity colonies start to enter homes.
So, how can these creatures actually make their way in?
“Since they’re able to squeeze through openings as tiny as a quarter of an inch in diameter, bats can access your home through a litany of places you might not expect, including small window cracks, small foundational gaps, and even openings for electrical wires that lead inside, vents, chimneys,” explains Jason Burkart, managing director at Critter Control in Marietta, GA.
If you notice scratching and squeaking at dusk or dawn, bats are likely in your proximity. Droppings (also known as guano) are another sign they’re in your home. “Guano is full of digested insect shells and crumbles to the touch thanks to its dry, dusty texture. You will find piles of it directly beneath where bats roost, often along attic beams or below soffit gaps,” says Bossel.
Other telltale signs of bats include an ammonia-like odor, which lingers in insulation, beams, and drywall. The smell is sharp, sour, and hangs around long after the bats leave. In a closed attic or crawlspace, that ammonia smell gets worse by the week. “
If you walk into an attic and have to step back for fresh air, start looking for bat activity,” explains Bossel.
Lastly, greasy streaks may appear when bats squeeze through tight spots.
“Their fur has oils that rub off on wood or siding. You may find a faint, dark smudge near the attic vent or below a roofline lip. If you follow that mark, odds are good you are looking at their front door,” adds Bossel.
Keep in mind that bats won’t break into your home in swarms. A small group of them, however, can quietly nest and multiply over time.
How to keep bats out—and why it matters
By being proactive through these tried and true strategies, you can reduce the risk of bats in your home and keep your home (and your loved ones) safe.
Seal all gaps larger than a half-inch near the roofline and siding
“If a gap near your roofline is wide enough to stick a pinky finger through, it needs to be sealed,” says Bossel.
That half-inch space is all a bat needs to squeeze in so you need to close off every spot with foam, caulk or heavy-gauge wire mesh.
Install chimney caps and attic vent covers
Install chimney caps and vent covers made for wildlife exclusion. A cap stops bats from dropping straight into the flue or attic.
Stainless steel vent guards last for years and handle wind, rain, and animal claws. If possible, do the install before dusk to avoid trapping bats inside by accident.
Replace damaged screens
“Damaged screens are just open doors. Even a 1-inch tear gives access. Bats follow scent trails from bugs and can detect heat inside,” explains Bossel.
Replace any torn mesh with metal screens. And don’t assume bats only go for attics—porch soffits and carports get hit, too.
Avoid leaving porch or attic lights on
Outdoor lights attract insects, and insects attract bats.
“If you run porch lights overnight in July, you are basically putting out the bat buffet,” says Bossel.
Motion-sensor lights or amber bulbs reduce bug traffic and keep the skies quieter. Plus, it cuts your electric bill, so it’s a win-win!
While it might take some time and effort to bat-proof your home, doing so is well worth it as bats can cause structural damage and pose serious health risks like histoplasmosis—a lung infection caused by bat guano.
Also, remediation does not come cheap. You can expect to pay anywhere from $1,000 to $5,000 for bat removal and cleanup. And no—killing bats or relocating them on your own probably won’t be an option.
“Many bat species are protected by state and local laws throughout the country that prohibit their removal during certain times of the year, when their pups are gaining the strength to fly on their own,” explains Burkart.
A trained professional will be able to handle bat removal and exclusion in a fashion that properly cooperates with all legal considerations.
What to do if you find a bat in your home
If you notice one of these flying critters on your property, do your best to stay calm and keep everyone away from it, including pets. Shut the doors to confine the bat in one room. Open a window or exterior door wide, turn off the lights, and stand back.
“Bats want out, so give them an escape route,” advises Bossel. “If the bat does not leave after 30 minutes, use heavy gloves, a box, and a stiff piece of cardboard to gently trap it, then release it outside.”
Whatever you do, never try to grab a bat with your bare hands. The risk of rabies is low, but you never want to gamble. If someone gets scratched or bitten by the bat, call your local health department immediately.
In the event of an infestation, contact a licensed wildlife removal professional. right away to get a proper inspection. Most pros use exclusion devices, allowing bats to exit but not re-enter.
“Exclusion is the go-to move here. Basically, it is a one-way flap installed where bats enter. They leave at night to hunt and cannot come back. You wait a few days, then seal the hole completely,” explains Bossel.
Most of these jobs run around $250 to $1,500, depending on height and access.
Wait until late August or September—after the maternity season to ensure a clean, ethical removal. By then, every pup can fly, and you avoid separating families. While it might be tempting to try poison or traps, Bossel highly discourages them.
“They die inside your walls, and the stench is a whole new bill,” he warns. “Do not waste money on ultrasonic gimmicks or sprays either, because the vast majority of the time, they don’t work.”