You don’t want anyone or anything living in your home except for family, right? But you may have uninvited guests living in your house, and you don’t even know it. That’s exactly what happened at MY house when the local bat population decided to move in make themselves comfortable for an extended stay. This post is a short story about our experience with bats in the house, what steps you must take to get rid of these pesky litter critters, and why you must understand how bats think in order to get rid of them. You can use their habits against them. If you do not know how a bat thinks, you will lose your “war on bats”, and over time, they will make your home uninhabitable.
Is Your Home in Danger of Bat Infestation?
We had zero experience with bats. If you live in a large metropolitan area or in the “burbs”, you probably have no experience with bats either. Where do you find these pests literally “hanging out” (pun intended)? In rural areas that surround metropolitan areas and cities as well as areas like mine – a sparsely populated area in the far Northwoods of Wisconsin consisting primarily of lakes and woods.
Bats live primarily in the woods. But if they can find a building to live in, they much prefer that over living in trees and caves. If you live in the suburbs and have woods nearby, these uninvited guests may choose to visit your home and move into its comfortable accommodations.
Bats follow the hordes of mosquitoes that result from consistent heavy rain that creates the perfect breeding ground for them – puddles of stagnant water and water standing in wet fields. If you are in a rural area and the mosquitoes are particularly bad during any given summer, the bats won’t be far behind.
The summer of 2013 has been a particularly wet season all across the USA, causing the mosquito population to explode. With a particularly endless supply of mosquitoes, the bat population also explodes as they move in for the banquet.
Houses that Bats Love
If you live in a new, tightly built house, you are still not safe from bats. Our house was newly built in 1999. It’s built of half-log, which means ½ log on the outside, a 2″ by 6″ insulated wall in the middle, and ½ log on the inside. This is how log homes are built in cold climates. The walls are 13” thick with the 3 1/2″ thick logs comprising most of that thickness and the 2″ by 6″ insulated wall making up the rest. The overall effect is to give the appearance of a full-log home but with tremendously more insulation and cold protection than you would find in a full-log home.
Log homes are tight, very tight. That is primarily due to the fact that water is a logs worst enemy. So every crack or gap between the logs are either caulked or chinked to keep water out. One would think that this extensive sealing would also keep pests out.
Older lap-sided homes are more prone to bat infestation. These older homes were not built as tightly as new homes are built. We thought that our home was impervious to bats. Not so.
What does this mean for you? If you live in an older home (pre 1970) AND live in the suburbs or a rural area, your home could be a target for the local bat population. They are probably eyeing-up your house at this very moment.
Bat Exterminators are a Humorous Bunch of Folks
I’m getting a little ahead of my story, but I asked a bat exterminator where my bats would go once they were out of my house. He took a look at my neighbors houses. One neighbor’s house had a roof with a steep pitch. He said that pitch is preferred by bats. But he wasn’t quite satisfied. Then he looked at the neighbors house on the other side of our house. He got really excited. That neighbor had a metal roof on his house. He pointed to my neighbor’s house and with a devilish grin on his face, he said, “That is where they will go next. Bats can’t resist a steel roof”. I asked him, “what do you do, follow the bats from house to house in order to expand your business?” He said, “That’s exactly what we do. You might want to give that neighbor my phone number. Because that is where your bats are going next”.
Why Should You And I Worry About Bats?
We asked ourselves that same question. Last summer, we thought it was pretty neat having bats around. They don’t bother people. And it was kind of fun sitting on the front porch at dusk watching them swoop back and forth as they consumed all the pesky mosquitoes around our house. Mosquitoes are a bats preferred diet. Bats can consume their weight in mosquitoes in one evening. Now multiply that by a dozen or so bats and your mosquito problem is pretty much handled. They are efficient mosquito killing machines.
But bats are not just occasional visitors to your home. We didn’t know that. We assumed that they lived in the woods. The fact of the matter is that they are not visitors at all. They lived in our house!
If bats are regular visitors to your house, it is likely that they are living IN your house. That’s where the problem comes in. If they are in your attic, they are hanging from your rafters upside down and building huge piles of guano (bat feces) under them. They are a “fertilizer machine”. When they are not eating or sleeping, they are pooping. In fact, they poop WHILE they sleep. Several animals are particularly adept at making fertilizer. Guinea pigs and rabbits are two animals that come to mind that are particularly efficient at pooping incessantly. Bats also reside in that same category.
You don’t want piles of guano in your attic, in your walls, or in the soffits that form the overhang of your roof. Guano doesn’t have an odor unless it’s wet. And it’s unlikely that anything in your attic gets wet. But when bat guano gets damp, it grows a bacteria that is harmful to humans. If that bacteria is inadvertently inhaled, it can be fatal to humans and pets.
Bats also urinate in your attic insulation. They use the inside of your attic as their personal toilet. If you permit that to happen for a couple of summers, it will smell and the insulation will have to be removed and replaced by a professional at considerable cost.
Just like rabbits, bats produce litter after litter of little bats. So if your bat problem started with just a couple of nuisance bats, there will be more nuisance bats sooner than you expected. The bat population will increase rapidly because bats have large and frequent litters.
Bats are destructive. Although they do not claw their way into areas of your house, and they do not destroy building materials by burrowing or gnawing their way through wood or sheet rock, attic insulation sticks to them. In their constant travels in and out of your attic, insulation is constantly being deposited on the outside of your home where it is useless.
Lastly, mosquitoes are well know disease carriers. Malaria and West Nile Disease are two of the most common diseases that they carry. Bats eat mosquitoes so bats are also efficient disease carriers. Unlike mosquitoes, bats don’t bite. In fact even though they are, how should I say this, “blind as a bat”, their efficient radar system allows them to avoid coming into contact with humans and other mammals. Nevertheless, do not touch bats and do not get near where they live unless you are protected from head to foot with gloves, cover-alls, respirator, hat and goggles.
Our Unwanted Guests Decide to Move In Permanently
Getting back to that first summer when we thought that our mosquito-eating little friends were cute, winter came and they disappeared. That was good because we noticed that they were increasing in number and the bat droppings on our covered front porch (photo #1, click to enlarge) were getting to be a nuisance. The droppings started coming into the house on the bottoms of everyone’s shoes. Guano was on the front porch windows. It stuck to the outside log walls. Worse yet, it was all over my favorite porch swing. The situation was getting way out of hand.
So that winter, we decided it was time to do a little research and find out if we had a serious problem. Our favorite research tool – the Internet.
Bat Research 101, Study
There are 1,240 species of bats. That news was not encouraging. We needed to identify the habits of the species of bats that had their eyes on our house as a potential “bat hotel”. Bats are mammals. In fact they are the only mammal capable of sustained flight. There are only two broad categories of bats: micro-bats and mega-bats. Ours must be micro-bats since they eat insects while mega-bats are fruit eaters with a couple of species of mega-bats who eat blood from other mammals (vampire bats) or eat the meat of dead mammals. We narrowed down the field of bat species to a big brown bat or little brown brown bat since both bat species are common in North America.
What we really wanted to know is if they went away for the winter. Do they migrate or hibernate? We got the answer that we didn’t want. They hibernate. That’s just great. That means that the little buggers are likely in our attic space, hanging from the rafters and pooping and peeing up a storm.
The article that I had located on the Internet confirmed my suspicion when I read that bats are capable of getting into any crack or opening as small as ¼ to 3/8th’s of an inch. That was not encouraging news. Even though our house was new and tightly constructed, ¼” crack could exist practically anywhere.
So they don’t migrate, they seek out somewhere warm to sleep through the winter, and they can get into ¼’ crack. That’s just great. The more that I learned about bats, the more I sensed a battle commencing in the coming summer; us against them.
While doing the research, my mind started to drift back to the years when I helped the contractors build our house in 1999-2000. I recalled a chimney flashing that didn’t quite fit the chimney pipe that exited our roof (photo #5). As a matter of fact, I recalled that pipe passing through our shed roof over the front porch where the flawed flashing left a gap of about a half inch between the flashing edge and the plywood roof. Dam! That must be where they are getting into my attic!
Bat Research 102, Take Action
I thought I should confirm if we had unwanted guests living in our attic. After all, it was winter. If bats were in the attic, they would be sleeping while hanging from the rafters. My wife wanted to put it off. She didn’t want to know since, in winter, there was nothing that we could do about the situation anyway.
I forgot to mention one very important factor in this whole matter. YOU CANNOT KILL BATS IN WISCONSIN and many other states. They are protected by law. I couldn’t believe it. They are not protected because they are endangered. They are protected because of the vital function which they perform – killing unwanted insects. I guess that makes sense. If the bats didn’t kill mosquitoes, we would be back to using the carcinogen, DDT to kill them just like in the 1950’s when, as a kid, I would watch at night as the fogging tractor went down the street every week in order to keep the mosquitoes in check.
I wanted to find out if bats were living in my attic, regardless of how my wife felt. That way, If I had a problem, I could find a solution and be ready for action in the spring. If I didn’t have a problem, then we could go back to our “bat watching” in the spring and not worry about it. I lifted the attic shuttle slightly and shined a strong flashlight inside the attic. I quickly slammed the shuttle door closed. We have a problem. Dozens of little bats hanging upside down from our rafters with little cone-shaped poop piles under them. The war on bats would begin in the spring.
If Bats Live in Your House, How Do You Get Them Out?
The rest of my research over the winter consisted of finding out how to get rid of them. I learned that getting bats out of your house is no easy job. The article that I was reading on the Internet said that the cost to have a professional get bats out of your house could easily run from $3,000-$10,000 and up, depending on whether you have a few bats or an entire colony of bats. Bat exterminators have to dress in sealed survival suits , rubber gloves, respirators, goggles, and helmets in order to protect themselves from coming into contact with potentially hazardous bat guano. I watched a bat exterminator in action on YouTube and realized that this was not going to be a simple, inexpensive job.
In addition to finding out how the bats are getting into your home and attic, bat exterminators must use canister vacuums in your attic in order to clean up the mounds of guano. The canister vacs also protect them from angry flying bats. They simply suck the bats up into the vacuum. But because they are not allowed to kill them, they drive to a remote area and release them. And, of course, they note where they release them because homeowners in the area will likely call them the following summer with a bat problem. This is a common tactic for bat exterminators. This is how they expand their business. No need for Facebook advertising in this instance.
Realizing that the cost of getting rid of our bats could be considerable, I called my home insurance agent to find out if this type of service is covered under my homeowner’s insurance policy. It was. But only the clean-up. Coverage did not include any building modifications to thwart bats in the future. The bat exterminator handled minor sealing of entry points. But our shed roof front porch would always attract bats unless it were redesigned.
Spring arrived and the first thing that we did in April was to find a bat exterminator. All the national services like Orkin or Terminix did not service our area. We finally found a local service called Diamondback Pest Control.
Diamondback’s bat exterminator came out in April and inspected the outside of our house. I told them about the suspect chimney flashing gap and they agreed that was likely where the bats were getting into the attic. But we needed to find other potential entry areas, so that once the chimney gap was sealed, the bats would not be able to simply move their “front door entry” to some other location.
Continuous ridge vent on a home’s roof (photo #2) is a favorite entry point for bats. All houses have ridge vents for attic ventilation. However, if the ridge vent incorporates a two inch thick inner lining that looks like a giant Brillo pad, that is sufficient to keep bats from using the ridge vent for entry. My ridge vent DOES incorporate one of these Brillo-pad linings. I could see the disappointment on the bat experts face. He informed me that he employs five crews of men who do nothing but replace ridge venting on homes. That’s an expensive job. I could tell that replacing ridge vent was Diamondback’s bread and butter, as my bat man became quite animated and excited when talking about it. He wanted to replace my ridge vent regardless of its ability to thwart bats.
He found no other entry points for bats on the outside of my home. But, at this writing, it is late July and we are still waging war to keep bats out of our house. More on that later.
Before you can seal up any bat entry point into your home, you must first get them OUT. Use of the canister vacuum cleaner in the attic doesn’t ever get them all. What makes getting them out easier is the fact that they must come out every evening in order to eat bugs. The whole idea of getting them out of your house permanently is finding a way to keep them from getting back in once they are out for their dinner.
This is where you must know something about bat habits and how they think. The Diamondback bat exterminator draped and stapled a net from the chimney opening of our shed roof over our porch all the way down to the overhang of the roof. At the overhang, he left an area of the net loose. Then he explained to me that the bats would come out the chimney opening as they always have. They would encounter the net and seek a way out, which they would find at the bottom of the roof where they would simply drop out. However, on return to my attic, bats expect to fly in level to the area where they enter a house. Bats are blind and use radar to find their way around. Their radar in conjunction with their habits does work well on the concept of going DOWN in order to go UP. So when they encounter the net, they will not think of looking further DOWN the roof for the hole in the net that they originally came out of, which leads UP to their house entry point. They’ll give up and begin their search for another entry point. Since the house was already inspected for additional entry points, they won’t find one. End of problem. Or at least, that’s what we thought.
Before I forget, here’s an interesting antidote. I know a lady in another area who used the screen theory above, at her house. However, she was not impressed with the law that says that you cannot kill bats. She placed a five gallon bucket of water below the loose area of the screen at the bottom of the roof where the bats would drop out. The bats fell into her bucket of water and drowned. She didn’t have to worry about her bats finding another way into her house, for obvious reasons.
Two weeks passed and the bat exterminator came back to remove the net and seal the crack where the chimney enters the house. He also installed a sonic device on top of the shed roof porch that emits a sound that bats hate. This would keep bats from perching in the tiny dark crevice where the shed roof over the porch meets the houses’ primary roof. Or so we thought.
The sonic device (photo #5, the black box) emitted a sound that was audible to humans. It sounded like crickets on steroids. Very annoying. I saw warm summer nights of enjoying our cozy front porch and swing disappearing quickly. Fortunately, we were not able to hear the sonic device inside the house.
The sonic device worked for about a month. After that, we spotted two bats sitting right next to it, asleep, while the device made it’s annoying chirping sound. A month after that, the sonic device bit the dust and stopped working altogether. We took it down and deposited it in the garbage.
In June, the Diamondback Pest Control service figured that their job was done. So they sent me a bill for $765; no where near the $3,000 minimum that we expected. We were delighted with the low cost of getting the bats out of our attic. But we still had bats in the house. This time they were in the soffit or overhang of the primary roof, yet still in the area of our (and their) favorite front porch.
When Your Bat Exterminator Gives Up, Be Prepared to Take Matters Into Your Own Hands
I need to interject at this point that bats are next to impossible to get rid of. The are persistent. When you think they are gone, they find another way in. Once you address that new entry point, they find yet another way in. If you have a bat problem that has not yet turned into full scale war, it will.
The pesky little critters found a tiny crack at the very top of our ½ log siding where the logs meet the overhang, and they wiggled in there. We knew what they were up to, because we found little balls of yellow fiberglass insulation on our porch below their new “front door”.
We were frantic at this point and using poor judgment. We envisioned pulling an army tank up to the front of the house and blowing the front porch clean off the house just to get rid of the bats. We bought an over sized mosquito fogger thinking that if we could put a dent in their food supply (the mosquitoes), they would be forced to go someplace else in search of food. That didn’t work. But it sure gave us some relief from the mosquitoes.
We boarded up the crack (photo #4), where they were getting in, temporarily, until we could make decorative moldings out of log material for permanent sealing. They responded by moving their “front door” to a ¼” crack that we didn’t even know about. The small opening was located where the beam, which supports the shed roof porch, meets and passes through the primary roof.
We knew there were bats still hanging around. We could hear them chirping back and forth to one another as we sat on our front porch. But we couldn’t figure out how they were getting in. My daughter took the initiative one night and sat on the front porch with a strong flashlight to see what the bats were up to after dark. She saw them disappear into the roof behind the porch beam. Otherwise, no one would have figured this out; not even Diamondback, the bat exterminators.
Diamondback considered their job to be done. They weren’t coming back. Since I wouldn’t let them replace all the ridge vent on my house, they were off in search of more lucrative work. We had to tackle the remainder of the bat removal job ourselves. Since I had learned some important bat removal secrets from my Diamondback bat exterminator, I was prepared to do this. After all, we have been engaged in this bat war since April and it is now late July – 4+ months to get rid of our bats, essentially the entire summer!
I draped some polyester screen (photo #3) over the entry point adjacent to the front porch beam, stapled it down securely and left it loose at the bottom for bats to drop out. They would not fly in to reenter since they could no longer enter their “front door” while in level flight. The screen would force them to go DOWN to the roof line and then UP to the crevice where they enter. They won’t do that since that is not their habit.
For some reason, that approach didn’t work. We adjusted the screen in several different configurations. But our determined bats seem to always find a way to get into that crevice. We lost our patience with them, after a couple of weeks, and then the crevice was sealed permanently.
The risk of sealing an entry point before all bats are out of your house is that they will die in your house if they are sealed in. If they die in your wall or your attic, they will eventually stink and attract other bugs like ants and flies. This war has been going on so long that I was willing to take that risk. As hot as it’s been this summer, I figure it shouldn’t take long for their little bodies to shrivel into a dried out potato chip size. And I can handle that versus spending another summer trying to get them out of my house.
While I was performing this one last act to bring the “bat” war to a close, I noticed that dozens of them had moved back into the crevice at the back of the shed roof where it meets the primary roof. The sonic device had forced these bats out of that area. But since the sonic device broke, the bats moved back in.
They chirped at me insultingly as I performed my work of sealing the crack adjacent to the beam. I looked at them in disgust and they did the same as if to say, “This is OUR home, not yours”. And then I lost it. I was tired of fighting bats all summer and I wasn’t going to take it anymore. I was mad. I grabbed the garden hose and a ladder, and turned the water on full blast. I blasted them out of that roof crevice and they went flying in every direction. The mounds of guano that they had deposited on my shed roof began to flow down the roof like a mud slide. It took me most of the afternoon to clean up the mess. The bats haven’t been back since. I don’t think that they care much for water and I soaked them pretty good.
But they’ll be back. So I ordered a better sonic device in preparation for their return. Were there bats in the crevice that I sealed next to the beam. I don’t know. I guess that we will find out one way or the other by fall. For now, the “bat war” is over.
So What Have You and I Learned from this Experience?
- If you live in an urban or rural area and see bats near your house, there’s a good chance they are inside your house.
- Bats are destructive. Bat feces is hazardous. Bats can make your home’s insulation useless.
- Bats can enter a hole or crevice ¼ to 3/8” in size.
- Inspect the outside of your house thoroughly if you suspect a bat issue. Better yet, get a bat exterminator to inspect your house for a nominal fee.
- Do not allow a bat exterminator to replace your roof ridge vent unless they can show you where bats have been entering your attic. Bat droppings are the best proof of entry.
- If you have bats in your attic, get an estimate from more than one bat exterminator. I’ve never met a bat exterminator that can be trusted.
- Bat entry points should be sealed once the bats are outside; never while they are inside.
- Allow bats at least a week to get out before sealing a point of entry.
- Note how your local bat exterminator rigs a system for allowing the bats to get out, but not back in. There’s a good chance that you will need to do this yourself in the future. Bats don’t give up easily.