What 25 Lehigh Valley Bat Jobs Taught Us About Bats in Your Home
Over the past several weeks, the County Pest wildlife team has inspected more than 25 homes throughout the Lehigh Valley for bat activity.
Different houses. Different neighborhoods. Different construction styles.
But we kept seeing many of the same things.
The biggest lesson? Bat problems rarely begin as major problems. They usually start with one small opening, a few bats, and a little guano in an attic or behind a piece of flashing.
Give them enough time, however, and that small opening can turn into years of accumulated droppings, damaged insulation, staining, odor, secondary insects, and a much more complicated cleanup.
Here is what 25 recent bat inspections taught us about bats in Lehigh Valley homes—and what homeowners should be looking for.
Lesson #1: Bats Can Make a Surprisingly Big Mess
Bats are small animals, but a long-term roost can create a significant amount of contamination.
One bat producing a few droppings may not sound like much. But when several bats return to the same roost night after night—and potentially year after year—the accumulation adds up.
During our inspections, we regularly find bat guano:
Along attic peaks and rooflines
On top of insulation
Behind siding and flashing
Inside soffits
Around chimneys
Behind shutters
Inside wall and ceiling voids
On exterior walls underneath entry points
In established roosts, insulation can become compressed or contaminated with guano and urine.
And this is where the cost of a bat problem can change dramatically.
A relatively new bat issue may only require finding the entry point, installing a one-way device, and permanently sealing the structure.
A roost that has existed for years may require exclusion, extensive repairs, guano removal, sanitation, and sometimes insulation remediation.
When it comes to bats, time matters.
The longer a colony is allowed to use a structure, the greater the opportunity for contamination to accumulate.
That doesn't mean every attic with a few bat droppings needs to have all of its insulation removed.
We believe recommendations should be based on what is actually present, not fear-based selling.
But heavy contamination is very different from a few scattered droppings, and a proper inspection should determine the extent of the problem before recommending remediation.
Lesson #2: Bats Don't Need a Big Hole
This is probably the biggest surprise for homeowners.
When someone pictures an animal entering an attic, they often imagine a broken vent or giant hole in the roof.
Bats don't need anything close to that.
A bat can take advantage of extremely small construction gaps, particularly where two building materials meet.
On many Lehigh Valley homes, the entry point looks completely insignificant from the ground.
The Most Common Bat Entry Points We're Finding
After inspecting home after home, several locations keep appearing.
Soffit Returns
This has been one of the most common areas we've encountered.
Where a soffit terminates against a wall, roof, dormer, or other architectural feature, small construction gaps can develop.
A dark opening at the end of a soffit may be all a bat needs.
Roof and Step Flashing
Flashing is designed to protect the home from water, but small spaces underneath flashing can provide excellent bat roosting locations.
We've seen this repeatedly on homes where roof heights change or additions meet the original structure.
Chimney Flashing
The intersection between a chimney and roof creates several potential gaps.
Older masonry homes throughout the Lehigh Valley can be particularly complicated because irregular stone, mortar joints, flashing, and roof materials create numerous potential openings.
Ridge Vents
Some ridge vents are extremely well constructed and properly secured.
Others develop gaps or are installed in ways that allow bats to get underneath them.
A roof-level inspection is sometimes necessary to properly evaluate them.
Fascia and Roof Edges
Small separations between fascia boards, roofing materials, trim, and soffits are another recurring entry point.
Dormers and Boxed Windows
Architectural features create intersections—and bats love intersections.
The more complicated the roofline, the more areas there are to inspect.
Behind Shutters
Not every bat found behind a shutter is entering the house.
However, shutters provide a protected, warm space that bats sometimes use for temporary or seasonal roosting.
We've also found situations where gaps behind shutters lead directly into larger structural voids.
Lesson #3: The Entry Point Usually Leaves Clues
Sometimes the actual opening is difficult to see.
Fortunately, bats frequently leave evidence behind.
Look for these signs around your home:
Dark staining or rub marks
Bats repeatedly entering the same small opening can leave dark discoloration around the entry point.
Guano stuck to siding or walls
Bat droppings may accumulate below an active roost.
Droppings on decks, roofs, patios, or window ledges
Look up. The entry point may be directly above the accumulation.
Small dark gaps around soffits and flashing
Pay particular attention to corners and transitions between building materials.
Bats appearing inside the living space
One bat accidentally entering a house can happen.
Multiple bats appearing inside over a period of weeks or months should raise suspicion that bats are using part of the structure.
Scratching or chirping near the roofline
Bats are usually much quieter than squirrels or raccoons, but colonies can sometimes be heard inside wall or attic spaces.
Lesson #4: Finding a Bat Inside Doesn't Always Tell You
Where the Colony Is
This is another important lesson from our inspections.
The room where a homeowner discovers a bat isn't necessarily anywhere near the exterior entry point.
Bats can move through:
Wall cavities
Plumbing and utility chases
Attics
Dropped ceilings
Unfinished crawlspaces
Gaps around framing
Openings between finished and unfinished areas
We've inspected homes where bats appeared in a bedroom or hallway, but the actual exterior entry point was several rooms away.
That's why simply sealing the room where the bat appeared doesn't necessarily solve the problem.
The building has to be evaluated as a structure.
Lesson #5: Every Bat Problem Doesn't Require the Same Solution
One of the most important parts of wildlife control is understanding the difference between removing an animal and solving the reason it got there.
Catching a bat inside the house addresses that individual bat.
It doesn't necessarily address the colony.
Spraying something into an opening doesn't solve the problem either.
And simply sealing an active opening can trap bats inside the building.
Proper bat control is exclusion.
A professional bat exclusion generally involves:
Identifying active and potential entry points.
Sealing secondary openings.
Installing a properly designed one-way exclusion device over active entrances.
Allowing the bats to leave naturally.
Removing the device after activity has stopped.
Permanently sealing the remaining opening.
The objective is simple:
Let the bats leave—but don't let them back in.
Lesson #6: Bats Are Actually an Important Part of the Lehigh Valley Ecosystem
We remove bats from houses.
We don't want to remove bats from the environment.
There is a big difference.
Pennsylvania bats are an important part of our local ecosystem and consume tremendous numbers of flying insects.
Their prey includes many night-flying insects, including moths, beetles, flies, and other insects.
That makes bats valuable natural predators.
Several bat populations have also faced serious pressure from white-nose syndrome, a fungal disease that has caused major declines in North American bat populations.
That is one of the reasons responsible wildlife management focuses on exclusion rather than unnecessary killing.
The goal should be to keep bats where they belong:
Outside, flying over our fields, forests, streams, farms, and backyards—not living inside your attic.
What Species of Bats Live in the Lehigh Valley?
Pennsylvania is home to several species of bats.
Species encountered in eastern Pennsylvania include:
Big Brown Bat
The big brown bat is one of the species most commonly associated with buildings.
They frequently use attics, wall voids, barns, churches, and other structures as roosting locations.
Little Brown Bat
Once extremely common throughout Pennsylvania, little brown bats experienced severe population declines following the arrival of white-nose syndrome.
They can still be found using buildings and other protected roosting locations.
Tri-Colored Bat
The tri-colored bat is one of Pennsylvania's smaller bat species and has also been heavily affected by white-nose syndrome.
Eastern Red Bat
Eastern red bats behave somewhat differently from many building-roosting species.
They commonly roost individually in trees and vegetation rather than forming the large building colonies homeowners typically associate with attic bat problems.
Several other bat species occur in Pennsylvania as well, which is another reason identification and responsible exclusion practices matter.
Lesson #7: Older Lehigh Valley Homes Can Be Especially Challenging
Our area has an incredible variety of architecture.
We inspect:
Historic stone farmhouses
Victorian homes
Brick row homes
Churches
Barns
Mid-century houses
Modern developments
Homes with multiple additions
Every addition, dormer, chimney, roof transition, boxed window, and soffit creates another building intersection.
And building intersections are exactly where small gaps develop.
We've inspected 100+ year-old houses that are remarkably tight and much newer houses with obvious bat openings.
Age alone isn't the determining factor.
Construction details matter.
Lesson #8: The Cheapest Bat Problem Is Usually the One You Catch Early
This may be the biggest takeaway from our 25 inspections.
If you see staining around a soffit today, investigate it.
If you're finding mysterious droppings below your roofline, identify them.
If you've had several bats inside your house, don't assume they're unrelated.
A small exclusion project today can prevent a much larger remediation project years from now.
Bat problems don't necessarily become emergencies overnight.
They become expensive slowly.
A few droppings become hundreds.
Hundreds become thousands.
Small areas of contamination become larger areas.
And a simple entry-point repair can eventually become an exclusion, cleanup, sanitation, and insulation project.
Humane Bat Removal in the Lehigh Valley
County Pest provides professional bat inspections, bat exclusion, one-way device installation, structural sealing, guano remediation, and wildlife-related attic restoration throughout the Lehigh Valley.
Our approach is based on a simple principle:
Solve the problem without unnecessarily harming the animal.
We inspect the structure, determine how bats are using the building, allow them to leave through properly installed exclusion devices, and permanently seal the openings responsible for the infestation.
When contamination is present, we can also evaluate whether cleanup, sanitation, or insulation remediation is actually warranted.
No scare tactics.
No automatically telling every homeowner they need a new attic.
Just an inspection, evidence, and a solution based on what we're actually seeing.
Think You Have Bats?
Look around the exterior of your home at dusk.
Watch your roof peaks, chimney, dormers, soffit returns, and flashing.
If you're seeing bats consistently emerge from the same area—or you've had repeated bats appear inside the house—there may be an established roost.
The sooner it is identified, the easier it usually is to correct.
County Pest
Where Service Meets Science.
Serving homeowners throughout Emmaus, Allentown, Bethlehem, Easton, Center Valley, Coopersburg, Hellertown, Whitehall, Nazareth, and the surrounding Lehigh Valley.
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