Building and installing a bat house can be a great way to provide cover for bats. Since many bats take shelter in trees, this can be a particularly good option if your garden does not have many mature trees nearby.
Read the tutorial below to learn about the requirements for an optimal bat house and how you can build and install one yourself. You’ll find helpful references to print out as well as follow along steps from our NWF bat house builder! Good luck!
The goal of a bat house is to create a shelter that mimics the space between bark and tree trunk. That means that a bat house should:
You can find a bat house construction plan from Bat Conservation International's website. (They also have a Bat House Builder’s Handbook available for free in a digital version on their bat house pages.) Note that the size of this bat house is quite large: two feet wide and almost three feet tall! A successful bat house can be smaller (14 inches wide instead of 24 inches wide), but this plan is designed to easily use up a 2 foot by 4 foot piece of plywood with fewer cuts.
Have you ever seen bat houses for sale that are smaller or shaped like a bird house? That just means those houses were made by people less acquainted with bat needs.
As you’re familiarizing yourself with the plan, ensure that you have a location with:
Interestingly, bats are less attracted to bat houses mounted on trees. There's a few reasons for this:
Bat houses mounted on buildings retain heat better and are less accessible to predators. You can alternatively put them on a pole.
If you’re following the Bat Conservation International plans, the supplies needed are:
Tools Needed to Build a Bat House
For those of you who do not normally buy wood, here are some tips:
In addition to the supplies on the plan, we also recommend the following:
Time commitment: 30 minutes
Measure and mark where you need to cut the wood according to the plan. Clamp it down to a sturdy spot for safety. You cannot safely hold the wood and the circular saw. Adjust the blade to the correct depth depending on the width of your wood. It takes only five cuts. Don't forget your safety glasses.
At this point, you can even take the wood and lay it together to get a sense of how it will look. You'll see that the bottom piece is the biggest. The 1x2 inch pieces form the sides of the bat house and then there are two smaller pieces of plywood on top. The gap between those two is a ventilation slot.
Time commitment: 2 hours
This may be the most difficult part of making the bat house, but it's the most important. The goal is take the plywood, which is very smooth, and roughen it up to provide places for the bat to crawl up into the house. You can do this by cutting grooves into the wood. If you are going to use plastic mesh to help the bats climb inside your bat house, now is the time when you will staple it on. Make sure it hangs all the way down to the "landing pad" area, so bats have something to grab onto.
A note on this step:
When it came time to cut the grooves, what I found challenging was that I didn't know what type of tool to use.
At first, I was shy about using the circular saw, so I tried to use a hand saw. After 30 minutes and only three grooves, I realized I would have to rely on technology.
I set the circular saw to only 1/16 of an inch, re-clamped the plywood and started cutting grooves into the backboard. They were not always perfectly straight lines, but that's not important because trees do not have perfectly straight grooves either.
Once I had cut grooves over the whole backboard with the circular saw, I took my hand saw and deepened some of the grooves. I did this because I was not sure if the circular saw went deeply enough and also to roughen it up even further.
Time commitment: 1 hour
Bats like it dark inside their houses so it's important to stain all inside parts a dark color. First you have to sweep all the sawdust carefully from the backboard, especially from the grooves that you cut.
It's important to use stain rather than paint because paint would fill in the grooves you just cut. Stain just soaks into the wood nicely.
It only takes two coats of the stain, and the stain dries fast if you are making your bat house outside in the sun.
Time commitment: 30 minutes
Before adding the side pieces, apply caulk. This seals the bat house to help keep the heat inside. Baby bats need a warm home - reaching 80 to 100 degrees Fahrenheit in July.
Next you use your power drill to attach the side pieces. Since these pieces are rather narrow, they can easily split. A way to avoid splitting is to pre-drill the holes with a drill bit that is smaller than the size of your screw. Then, when you drill in the screws, they go in much easier and your wood stays whole.
Time commitment: 30 minutes
Next, attach the top two pieces of plywood. First caulk to ensure a snug fit. Then follow the same advice for drilling and attach the larger of the two top pieces.
Before you attach the smaller of the two pieces, measure to make sure your ventilation slot is about half an inch.
Time commitment: 15 minutes
To ensure there are no gaps between all these pieces of wood where heat could escape, leaving our poor bats shivering in the cold, put some caulk all around the sides in any gaps that you see.
Finally, add a piece of wood to the top to form a roof.
Time Commitment: Variable given paint drying time
Finally, we need to ensure the bat house lasts a long time, so we prime and paint it. We prime it with an exterior primer that discourages the growth of any plants or mold. Once the primer dries, paint the dark paint.
Time commitment: 20 minutes
Bat houses should be mounted on poles or buildings, which provide the best protection from predators. Wood or stone buildings with good solar exposure are excellent choices, and locations under the eaves often have been successful. All bat houses should be mounted at least 12 feet above ground, but 15 to 20 feet is better.
We hope you enjoy building your bat house, whether it's in celebration of bats at Halloween or any time of the year. Remember, once you put up the bat house, it may take a few years for a bat to find it. They will come looking in the springtime, so ideally it should be hung by late winter.
When you provide habitat elements, like shelter, for bats, you’re also supporting many other wildlife species that need your help! You may even be ready to get your garden recognized as a Certified Wildlife Habitat®!
By taking a few simple actions, you can make a difference!
Take Action Today!