The Suburban Bat House
Specifically designed for Urban and Suburban areas.
I make my living by evicting colonies of bats (very gently of course) from houses in suburban areas. I find that most of my customers truly like bats and many are fascinated with them.. On almost every job I hear - "We like bats, I mean, we realize that they eat mosquitoes and that they are an important part of the environment but we just don't want them in our house!" Then I am asked the Bat House Question - "We'd like to keep the bats in the area to eat the mosquitoes. What if we put up a bat house? Would that make them stay?"
For years I have told my customers not to bother buying and installing traditional bat houses in our area because the success rate associated with them is so low in our area. I have never been comfortable telling people "No, bats in our area very rarely use traditional bat houses" so I was always researching ways to create a bat house that would actually work in Massachusetts and Rhode Island.
Suburban Bat Colony Research
In an average year I will inspect over 300 houses that are infested with bats. This has given me the opportunity to study and document the ways in which bats enter and exit houses in suburban areas. I have found that most common entry-point and/or landing area on a house is the gable vent. Bats find these vents so attractive because they provide both shade and a constant air-flow from the attic. Bats will land on the blades of these vents and then crawl inside. If the factory bug screen on the inside of the vent is loose or missing the bats will make their way into the attic. If the bug screen on the inside of the vents is intact the bats will not be able to gain access to the attic but they will still roost under the blades and use the vent as an exterior roost as shown in the pictures below. Bats will roost behind these blades of the vent during the daylight hours and leave shortly after dusk to go out and feed on mosquitoes only to return before daylight to repeat the process.
Fact 80-90% of the bat population in suburban areas resides in houses, attics and other man-made structures.
How it started
In July of 2004 I performed a bat removal service at a home in a small sub-division and evicted a few dozen bats that were entering through the gable vents. Two weeks later I got a call from their neighbor that lived two houses down. She now had these bats in her gable vents and also wanted them evicted. Then while I was doing that job I nudged two bats out of the gable vent that I was working on and watched them fly in a big circle and enter the vent in the next house over. I already knew that bats were attracted to gable vents but this job showed me just how much these bats seek them out and are trained to use them.
Theory
If these suburban bats are so determined to roost in gable vents than why not build a bat house that closely resembles one? I began experimenting with different designs and finally settled on a very simple design that closely resembles a gable vent. I have since installed the Suburban bat house in a variety of different situations. In houses that already had a history of bats I had 100% success. The bat houses were used by bats in a matter of days.
When installed correctly, the Urban Bat House out-performed the traditional bat house in Suburban areas 10-1. I attribute this to the gable-vent design of this bat house and the fact that bats in suburban areas are trained to use gable vents. The Suburban Bat House also has one critical component that no other bat house has: Air-Flow This bat house uses the constant air-flow from the attic to attract bats and keep them coming back.
Fact - Traditional bat houses in Massachusetts and Rhode Island have less than a 5% success rate in attracting bats. They do however have a great success rate at attracting wasps and hornets!
Air Circulation
The reason that gable vents are installed is to allow houses and attics to breath. Air enters in the soffits below the gutters and rises through the attic and exits through the gable vents. Air flow is the main factor that attracts bats to gable vents. Bats can sit in these vents and have air constantly moving over them. Traditional bat houses are simply wooden boxes and have no ventilation and no air flow whatsoever. This is why bats prefer to roost in gable vents over bat houses or anywhere else for that matter.
In many cases I have evicted groups of bats from a gable vents and installed a traditional bat house in close proximity to the secured gable vent (as pictured above) in an effort to get the bats to inhabit the bat house. Every time I have been disappointed when I returned weeks later to find no activity at all in the traditional bat house. Why? Because traditional bat houses do not have air-flow.
Suburban Bat House Design
The idea behind this bat house is rather simple- Install a gable-vent with a roomy, well-ventilated chamber for bats OVER the existing gable-vent that the bats are already using (or will be soon be using when they locate it). When the bats return to the gable-vent they will hardly even notice the difference. The bats will continue to inhabit the bat house but are not able to get into the attic. You get all the benefits of having bats in your yard without worrying about the getting into your attic. The pictures below illustrate the design of the Suburban Bat House.
How bats use the Suburban Bat House
Below is a short video summary that describes how bats use the Suburban Bat House.
You can expect to see bats residing in these types bat houses from late April until mid-October depending on the daytime temperatures.
Will the bats get into my attic?
No. The screening on the inside of the bat house prevents bats from getting into the attic. The bat house is designed so that the bat droppings will fall out of the gable vent and not into your attic.
Why install the bat house over the gable vent? Why not just mount it on a pole or screw it to the side of the house?
There are many benefits to installing the bat house in this area:
- Air-Flow- By installing the bat house over your gable-vent your provide bats with a constant air-flow from the attic. Lack of air-flow is the reason that 95% of traditional bat houses fail.
- Performance- If bats were using your existing gable-vent to enter your attic or just as an exterior roost you should have close to a 100% success rate for getting bats to use your Suburban Bat House.
- Almost Invisible- Once installed and painted to match the house the Suburban Bat House is almost invisible. It only sticks out 5 inches from the side of the house.
- Easy Installation- It takes a little bit of carpentry skills to install the Suburban Bat House correctly but it is much easier than erecting a 20-foot steel mounting pole in the middle of your yard for a traditional bat-house.
- Low-Maintenance- The Suburban Bat House requires very little maintenance. A quick trip up a ladder to clean out any bee/wasp nest each year is all that it needs.
**Installing the Suburban bat house over an existing gable vent will not restrict the ventilation of the attic in any way.**
Ordering/Purchasing Information
By now you're probably thinking "Great, but how much does it cost?"
They're free. No really. I am not selling them. Instead I am posting these plans here on BatGuys.com for anyone to use for free. Anyone with some basic Carpentry skills should be able to build and install one of these bat houses relatively easily. I am providing these plans because I would love to see homeowners use this design to provide Suburban bat colonies with places to roost. All I ask in return is that you take some pictures of your installed bat house and send them to me.
I would love to build a few hundred of these houses and install one at every bat removal and exclusion project that I perform but I just don't have the time to build them. During the summer months we are inundated with calls for bat control and I can't afford to be building, painting and installing bat houses when I have people calling me screaming because they have bats flying around their living rooms.
Proceed to Free Bat House Plans page
Matthew Grady
BatGuys Wildlife Services
Questions? Comments? Contact me using the information on our Contact page.
