What Works and What Doesn’t for Bat Problems
When homeowners find bats in the attic, walls, basement, bedroom, or living space, they start looking for a quick fix.
I know what your thinking…..
I have been doing bat control work for 38 years, spoken with tens of thousands of homeowners, and worked on thousands of residential bat problems.
I know that almost every homeowner will initially consider the same five or six cheaper, simpler ways they might be able to fix the problem themselves.
Bat houses, sonic devices, mothballs, sprays, sealing a few holes, or hoping the bats will leave on their own all sound tempting when the proper solution costs real money.
The article below explains what actually works, what does not work, and why complete bat exclusion and bat-proofing are the only reliable way to solve a bat problem.
Homeowners Want A Simple & Cheap Solution.
And they almost always try one of these inexpensive, simple solutions before hiring a specialist. When faced with the cost of properly done bat control work, it is completely understandable that people first gamble on cheaper products, shortcuts, and quick fixes.
The manufacturers of these products know homeowners want an easy answer, which is why millions of dollars are wasted every year on useless bat-control products sold to people desperate for a cheaper solution. Unfortunately, all those cheap bat-control products and cures are garbage.
Over the years, almost every client who calls me has already wasted money on these trash cures first. They have put up bat houses, plugged in sonic noise makers, dumped mothballs in the attic, sprayed repellents, sealed random holes, or hired local wildlife companies that promised a quick and inexpensive fix.
None of those things solved the problem.
The bats were still using the structure because the house still had openings. Until the bats are properly excluded and the home is properly bat-proofed, the problem remains.
However, There is Only One Cure That Actually Works
![Custom excluder installed over bat entry/exit point near bradford ontario - [ ] By Bat Control Specialists Canadas No1 bat control and bat removal company.](https://batcontrolspecialists.com/wp-content/uploads/2026/06/IMG_2469-edited-1-scaled.jpeg)
Bat-proofing means sealing, screening, flashing, or otherwise protecting the vulnerable areas of the structure so bats cannot continue using the house.
Bat exclusion means allowing the bats to leave through properly installed one-way devices so they cannot re-enter.
One without the other is not enough.
An excluder may get bats out of one opening, but if the rest of the house is still full of gaps, the bats can simply move to another area. Sealing gaps without proper exclusion can trap bats inside the structure and make the problem worse.
It has to be done at the same time.
But First Lets Talk About What Doesn’t Work
1. Find and seal the spot where they are getting in.
The Myth of Finding “The One Spot”
Many homeowners who call me think bat control is much simpler than it really is. They assume all we have to do is find the one spot where the bats are getting in, put an excluder over that opening, maybe seal a few other obvious gaps, and the problem will be fixed.
That is exactly why people buy cheap plastic bat excluders online. They think, “If I can just figure out where the bats are getting in, I can put this one-way door over the hole and solve the problem myself.”
Unfortunately, that is wishful thinking.
Residential bat problems are never that simple.
Big brown bats, our most common species in Ontario homes, are highly transient. They often live in small colonies and move back and forth among several houses in the same neighbourhood. Finding the exact opening they are using can be extremely difficult. Homeowners regularly do night watches and never see the bats come out. Even when bats are using a house, they may not exit in an obvious way, at an obvious time, or from an area that can be seen from the ground.
And even if you do get lucky and find the main entry point, putting one excluder over that spot does not mean the house is bat-proofed.
All houses have many other gaps bats can use. Some are around soffits, fascia, chimneys, vents, siding, flashing, roof edges, trim, and roof intersections. Many are hidden, high up, tucked behind materials, or impossible to see from the ground. If the bats are excluded from one opening but the rest of the structure remains vulnerable, they can simply move to another gap.
Seal a couple openings and pray?
At that point, the homeowner is playing bat-control whack-a-mole.
Seal one spot, and they move to another. Cover one opening, and they find the next weakness. The problem continues because the house was never properly inspected, excluded, and bat-proofed as a complete structure.
Real bat control is not about guessing at one hole and hoping for the best. It is about understanding how bats use the entire house, identifying the active and potential entry points, excluding the bats safely, and bat-proofing the structure so they cannot keep coming back.
When we are called in to fix the work of other companies, we usually find the same problem every time. Someone sealed a few obvious holes, maybe installed an excluder, and assumed that would be enough to fix the bat problem.
When it did not work, some came back and made an even bigger mess. Most simply bailed and left the homeowner with the same bat problem they had before.
The issue is always the same: the house was never properly inspected and bat-proofed correctly. The secondary gaps and potential entry points were ignored or missed, and if excluders were installed at all, they were often dumb, dangerous, badly made excluders installed in the wrong places.
2. Bat Houses
If only they worked.
Bat houses will not remove bats from your attic, walls, soffits, chimney, basement, or living space.
A bat house may sound like a nice idea, but it is not a solution to a bat problem inside a home.
Bats will not move out of a warm, protected, familiar structure just because someone puts a small box on a pole or tree nearby. If bats are already using your house, your house is the roost they chose.
Putting up a bat house does not seal the entry points. It does not exclude the bats. It does not stop bats from getting into the attic or walls. It does not stop them from showing up inside bedrooms, basements, bathrooms, or living rooms.
A bat house is not bat control.
Will they magically move out of your attic if you put one up? Heck no.
Your house is the bat-house.
Bottom line, bats don’t know what a bat-house is, its not an upgrade for them.
Will they use it at all? Maybe. But In my experience, that almost never happens. Very rarely do we find bat houses put up by customers that are actually being used by bats. Even when bats do use them, it is usually only occasional or periodic, much like bats may temporarily hang behind shutters, loose flashing, trim gaps, or other sheltered spots around a house. Most of the time, the bat houses our customers put up are never used at all.
And bats they won’t choose it over your home. If someone tells you they can cure your bat problem by selling you a bat-house, they are a crook or very misinformed.
What Doesn’t Work
3. Sonic Noise Makers
Sonic and ultrasonic bat repellers are a scam.
There is not much else to say other than they are sold to homeowners who are desperate for an easy answer, but they do not fix bat problems. If sonic devices worked, professional bat specialists would not be needed. We are needed because they do not solve the problem.
A noise maker does not seal a soffit gap. It does not protect a chimney. It does not close a roof edge. It does not repair a vent. It does not stop bats from moving through walls, attics, or hidden spaces.
The bats may ignore it, move temporarily, or shift to another area of the structure. But as long as there are places the bats can get into the house, the bats will remain.
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What Doesn’t Work
4. Mothballs
Mothballs do not solve bat problems.
They are not a bat control method, and they do not make bats permanently leave a structure. Even if a strong smell bothers bats temporarily, it does not close the openings they are using.
The house remains vulnerable.
Mothballs can also create unpleasant odours inside the home, especially in attics, walls, basements, and enclosed spaces. Instead of solving the bat problem, homeowners may end up with both bats and a chemical smell.
Guess what happens if you pour lots of mothballs into the attic?
Over the years, I have had several clients try to drive bats out of their attic by dumping large amounts of mothballs into their attics. It did not drive the bats out. It drove the homeowners out.
The smell became so strong that they could not live in the house, and they then had to pay someone in protective gear to remove all the mothballs before they could move back in.
Meanwhile, the bats simply moved down into the walls and hid from the stench. Mothballs do not solve bat problems. They just create a second problem.
What Doesn’t Work
5. Spray Repellents
Spray repellents do not fix bat problems.
You can spray a product into an attic, but most bats in houses are not simply hanging out in the open attic space waiting to be sprayed. They use attic areas as night-roosting spots and as a toilet, while their real roosting areas are usually hidden in inaccessible places such as wall cavities, soffits, gaps between floors, and other concealed structural spaces.
There is no practical way to spray repellent into every wall cavity, floor space, soffit void, and hidden area where bats may be living. Spraying around an opening will not stop them either. Bats enter and exit buildings quickly, and spraying something on the outside of the house is a waste of time and money.
Spray repellents are just another useless shortcut. They do not fix the real problem..
A spray cannot stop bats from using a structural opening. It cannot protect a roofline, chimney, soffit, siding gap, vent, or wall cavity. It cannot prevent bats from returning to a known roosting area if the house remains open.
Repellent sprays may make the homeowner feel like something has been done, but the actual problem remains unchanged.
The bats are using the structure because the structure gives them access, shelter, and protection.
Sprays do not close bat entry points. The structure still has to be repaired and bat-proofed.
The structure must be fixed.
What Doesn’t Work
6. Bright Lights
Bright lights are sometimes suggested for bat problems, but they are not a real solution.
Bats may avoid a brightly lit area temporarily, but they can often shift deeper into the structure, move to another part of the attic, or continue using hidden wall and soffit spaces.
Lights do not exclude bats. Lights do not seal gaps. Lights do not bat-proof a house.
If bats are using your home, the access points still need to be found and fixed.
Lights may disturb bats temporarily, but they do not solve the structural problem.
What Doesn’t Work
7. What Doesn’t Work: Denial
Ignoring a bat problem does not make it go away.
Most residential bat colonies are small and transient. You can go years without any showing up inside your home. Even though they are still living in your walls and attic. You may then get a bunch inside in a short period of time. Why? Populations go up and down. They may move to another house for a while. They come back. They definitely won’t show up inside every day. But one will show up eventually.
As long as the structure remains open, the problem will continue.
And bat problems involving little brown bats will definitely become worse over time because, they tend to form large colonies and return to the same houses each spring. Local little browns usually start out by scouting and exploring your house and it grows from there.
Hoping the bats will leave on their own is not a plan.
If bats are using the house, the house needs to be inspected.
A small bat problem is still a bat problem and may grow larger if the structure remains open.
What Does Work?
Only One Thing Works. Batproofing & Bat Exclusion
Part 1. Proper Bat Exclusion
Proper bat exclusion uses one-way exits that allow bats to leave the structure safely.
The goal is not to trap, poison, scare, or kill the bats. The goal is to let them exit naturally and prevent them from getting back through the same opening.
A proper bat exclusion should include:
- Finding the active entry points
- Figure out what species you are dealing with
- Preventively bat-proof the rest of the house before installing excluders
- Install the right number of excluders in the right places
- Allow enough time for bats to leave
- Avoiding exclusion during unsafe times when flightless young may be present
Photo of an active bat entry/exit point.
![before photo of a Bat entry & exit point in the fascia board of a bradford ontario home- [ ] By Bat Control Specialists Canadas No1 bat control and bat removal company.](https://batcontrolspecialists.com/wp-content/uploads/2026/06/Bat-entry-exit-point-before-view.png)
Photo of a correctly installed aluminum bat excluder.
Quality
Ready for action
A cheap excluder slapped over one obvious hole is not a proper bat job.
What Works: Part 2. Permanent Bat-Proofing
Bat-proofing is what keeps the bats from coming back.
Most bat problems are structural. Bats are using gaps around soffits, fascia, chimneys, vents, siding, flashing, roof intersections, roof edges, brickwork, or other parts of the house.
![bat-proofing work inside a cottage porch in whitelake ontario - [ ] By Bat Control Specialists Canadas No1 bat control and bat removal company.](https://batcontrolspecialists.com/wp-content/uploads/2026/06/65FFDDB4-58FD-4755-89AA-7FDA3A3923C2_4_5005_c.jpeg)
Those areas have to be protected properly.
Bat-proofing involves:
- Using correct caulking and sealants
- Screening and modifying vents
- Sealing soffit and fascia gaps
- Protecting chimney areas
- Installing custom flashing
- Repairing vulnerable roof edges
- Closing gaps around siding, trim, brick, and vents
- Protecting roof intersections and hidden openings
Proper bat-proofing is not just “filling one hole.”
It requires understanding bats, houses, construction materials, weather exposure, rooflines, siding, brickwork, soffits, fascia, flashing, and how different parts of the structure fit together.
Proper exclusion and bat-proofing are the only reliable ways to stop bats from using a house.
Before and After: What Actually Fixes the Problem
Before and after photos are one of the best ways to show the difference between temporary gimmicks and proper bat-proofing.
Before
Before we did work photos
After photos of repairs by bat control specialists
A caulking bead is applied along the soffit and brick joint to seal a potential bat entry point.
Before
After
Unprotected
Protected
Broken
Fixed
Wrong
Right
Unscreened
Screened
Uncaulked
Caulked
They enter here
They exit here
This stops them
Missing flashing
Replaced
Bat control is not about gadgets or repellents. It is about finding the entry points, excluding the bats safely, and bat-proofing the structure.
Why Gimmicks Keep Getting Sold
Gimmicks sell because homeowners want an easy solution.
A plug-in device, spray bottle, box, smell, or simple trick sounds much easier than inspecting and bat-proofing a house. Unfortunately, bats are not using the house because of a smell or a sound. They are using it because the structure gives them access to shelter.
Until that access is fixed, the problem remains.
That is why real bat control is a structural job.
The Correct Order for Bat Control
A proper bat control job should follow the right order:
- Inspect the structure.
- Find the active entry points.
- Identify vulnerable secondary gaps.
- Bat-proof the structure so they cannot return.
- Install humane bat excluders where needed.
- Allow the bats to leave safely.
This is what works.
Everything else is a distraction.
Need a Bat Problem Fixed Properly?
If you have bats in your attic, walls, basement, bedroom, or living space, do not waste time and money on bat houses, sonic devices, mothballs, sprays, or wishful thinking.
The only reliable solution is proper bat exclusion and permanent bat-proofing.
Bat Control Specialists inspect the structure, identify how bats are getting in, exclude them safely, and bat-proof the areas they are using.
For A Free Estimate
Fast, humane, guaranteed bat removal. Serving London and the surrounding area