Bats are amazing creatures. One bat can eat upwards of 1000 bugs, including mosquitoes, per hour. Living in an agricultural area, on an alluvial plain that is crisscrossed by streams, means that mosquitoes are always a pest around my house, making bats the best, natural, method of pest control.
I've made a few simple bat box homes in the past, but they are weathered and leaky, keeping the local bats from using them, and so I decided it was time for a new one. This is a simple, single chamber design using a mixture of recycled and new boards recovered from a shed build, and should house a good selection of bats for my needs. There is a slanted roof on the box, but due to the 'logo' on the front, it will tip toward the back, rather than the front. A 'runway' hangs down 4" from the body of the box allowing a place for the bats to land as they enter the box.
To be a bit different, I decided make a true 'Batman' box, using a design based on the 1940's version of the logo. This was more than an aesthetic choice as it was really the only one large enough to act as the front cover of the box. You can choose a different version, but it's good to be certain that it'll fit the size of box you're creating.
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Step 1: Tools and Supplies
- Table Saw
- Jigsaw or scroll saw
- Palm Sander
- Drill and Bits
- Measuring Tape
- Utility Knife
- Straight Edge
- Sanding Belt
- Staple Gun
- 2 12"x17" Pine or Cedar Boards for the logo
- 12"x17" Board for the back
- 2 17.25"x1" Pine or Cedar Strips for the sides
- 2"x12" Pine or Cedar Strip for the top
- Nylon Mesh Screen
- Poster Board
- Exterior Calk
- 1.5" Deck Screws
- Paint or Wood stain
Step 2: The Logo
As mentioned before, I decided to go with a traditional 40's version of the Batman logo and, lacking any poster board, I cut it out of some foam core I had laying around. It was easy enough to do one side of the board, then fold it over and use the edge I'd cut out to mirror the other half.
After some checking and re-checking, I realized that the logo would be a bit short for my needs, and considered making it somewhat bigger. I finally decided against it, as I didn't want the width to be excessive, and so I, instead, decided to lengthen the design, by roughly 2". It's not precisely a 'Batman' logo, in the strictest sense, but It's unmistakable in what it represents. This also serves to avoid copyright, on the design, as it differs enough as to be unique. The overall size of the Logo is 17" from tip of ears to tip of tail and 17" from tip of wing to tip of wing.
Step 3: Cutting and Shaping the Logo
Using the template you've created, trace it on your board. I started off using some 12"x17" pieces, and so my design spanned both sections. This works out good, as you'll see later as the split will act as 'ventilation' for the house.
Using a jigsaw or a scrollsaw, start cutting out the shape of your bat logo. If you decide to use a jigsaw, it's best to clamp your logo down to a table to avoid it moving as you work and causing you to cut the piece improperly. Don't try and turn corners with your jigsaw. Take nibbles out of sections removing enough so that you can follow the next contour as closely as possible. The scrollsaw is much better at this as it's narrower blade is more able to make sharp turns as you're cutting, however I've found that they tend to bend cutting thicker pieces of wood which can ruin the symmetry of your piece.
Once your pieces are cut out, it's time to start sanding the edges. you can use a belt sander, if you have one, however, if not, it's time to break out some elbow grease. A palm sander can help, but it can be tricky getting into tight spaces.
Once your piece is sanded, set it aside to start on the back.
Step 4: The Back, Sides and Top
As mentioned before, the roof will angle downward 20 degrees toward the back of the box, rather than the front. This is a plus as it will direct water away from the front of the box making the home a bit more livable for the bats.
To start, you'll need to cut your backboard with a 20 degree bevel on one end. The bevels long side will face toward the inside of the box measuring 17", making the outside 1/8" shorter. I was working with a scrap 12" piece of wood and made this in two sections, but you can use a solid 12"x17" piece of wood if you have one available.
**Note** Due to the shady practices in the lumber trade, most boards that you buy that claim to be 12" are actually only 11". Based on much of my research, bat houses should have, roughly 12" of roof, and so using an off the shelf 12" board may force you to build the back in two sections as I did.
The sides are two 5/8"x1"x 17.25" strips with a 20 degree bevel that lines up with the bevel on the back board. Again, due to the lumber trade, they are 5/8" rather than 1". I ended up cutting mine from a 1.5" piece of stock I had on hand.
The top is 2" wide by 12" long and is made from the leftover length used from cutting down the back board and is double beveled on each length. The bevel should run the same direction on both edges.
Step 5: Attaching the Sides and Top
Pre-drill holes down the edges of your back board roughly 4" apart and 3/8" in from the edge. This will prevent your screws from splitting the wood and ruining your piece.
Next apply a nice bead of silicone along the edge of the sides that will be screwed to the back and set them into place, using deck screws to attach them. Wipe away any excess silicone that squeezes out of the seam.
Finally, pre-drill holes for your top and again, applying silicone, screw it into place.
**Reminder** don't forget the bevel goes toward the back of the box, not inward toward the front.
Step 6: Installing the Screen
The bats are going to need something to cling onto as they hang inside the box. This can be accomplished two ways; The first is to score the inside of the box using a circular saw, which gives them small 'holds' that they can grab onto, and the second is to install some nylon mesh screen. I opted for the screen, as I felt it looked more tidy however this option is entirely up to you.
Cut a piece of nylon mesh the size of the inside of your box and, using a stapler, secure it into place. Make sure it is stretched nicely and flat against the back.
Don't staple the bottom half of the mesh down if you intend on painting or staining your box. You don't want to paint the inside so this will allow you to finish building it, rolling up the mesh, out of the way, so that you can paint the runway.
Cut two more pieces and attach them to the inside of the two logo sections. You'll have to trace the contour of the wings and for me, it was easier to staple the strip into place and use a utility knife to cleanly shape it around the curves.
Step 7: Attaching the Logo and Mounting Bar
This is the easiest step of all as you only have to line up the logo onto the box. Again, using your silicone, lay a bead along the top and side pieces where they meet the front. Before doing so, it's a good idea to see how far the front board sits as you don't want to apply silicone down any farther than necessary.
Once your top section is installed, you can install the bottom of your wing section, leaving a 1/8" gap as ventilation. Again, only apply as much silicone as needed, being certain not to get any on the runway.
As an extra measure of weather proofing you can apply some calk on the heads of the screws. This will prevent water from getting between the screws and wood causing rot. If you prefer, you can use some wood filler to smooth the screws over on the face, but this isn't necessary. Lets face it, it's a bat box. Bats don't care about screw heads.
Next, attach a 2" board, extending 3-4" from the top and bottom of the box on its back side. This is for securing it to whatever you plan on attaching it to. There are other alternatives for mounting your box, but this is a tried and tested method I've made on many boxes allowing you to screw, or (if you're concerned about your tree) tie it into place, very securely. Yes, I've had people, that I've made bat boxes for who were concerned about harming their tree so this became a natural alternative that allowed them to tie it to the trunk without damaging the tree.
When all is said and done, it's time to start sanding, especially if you intend on painting or staining. There's really no need to go below 150 grit paper because, as I mentioned before, it's a bat house.
Step 8: Painting or Staining
There's quite a bit of opinion on whether painting, staining or leaving natural is better. Having built nearly a dozen boxes, I honestly don't think it matters, tho some weather stain will help it last longer, and the bats don't seem to care either way.
The only real suggestion, with regards to paint, is the color, and depends on the climate you live in. Bats like warmth. Sometimes upwards of 100 degrees F. If you live in warmer climates, a lighter color paint would be better, while colder climates mean that the box should be darker. Because I live north of 45, it allows me to paint mine black which works well with the design.
It's entirely up to you how you paint/stain, but keep in mind a successful bat house should be warm and dry.
**As mentioned before, I left the runway mesh unattached so that it could be rolled up for painting. It's better to leave the inside of the box unpainted, so this allows the exterior to be painted leaving the internals unfinished. Once the paint dried, I finished attaching the mesh on the runway using staples.
Step 9: Finishing Touches
To ensure that there is no potential for leaking in the box, it's good to follow up with a bead of silicone around the edge where the logo meets the box. It's probably better to do this before painting, but since it will be out of view, it really doesn't matter.
Finally, adding some shingle material to the roof is a good idea, but not essential, tho it will go a long way to preventing leaking water from getting into the box. Cut it to the shape of your roof and use your silicone to 'glue' it into place. You can use staples to add a bit of extra strength.
Step 10: Finished
That's it, you're done.
Now you have a functional yet interesting house for the bats to keep your yard bug free. As you can see, I mounted mine low for picture taking, and when I get the courage, I will be mounting it much higher up on the tree. 20' is the best idea, but you can go as low as 10' if necessary. Just remember, you don't want anything to be able to disturb the bats so mount it somewhere it won't be interfered with.
As usual, I hope you enjoyed the instructable and thanks for following.