Building a Bat House

I've lived in many states across the US over the years since my family was an Air Force family. We have always seen bats at night and even had a few fly into the house, sunroom or get stuck under an awning roof. We have never had the problem of the bats roosting in the eaves of our house until we moved to Michigan. 

I wouldn't have minded so much if the bats were a clean animal, but they are not. The eaves of our house hang over our deck in the front and rear of the house and the bats seem to poop their body weight nightly. I decided to build a Bat House in the hoped of attracting the bats away from the house and to maybe get a few more bats and keep the bugs down a bit more (mosquitos are really bad out here.)

Here is a picture of what the Bat House looks like finished for those of you not interested in the construction of the project. If you want to see how it was built, keep on reading.

The first step after coming up with a plan was to cut out most of the pieces. As you can see in the picture below all pieces are cut from a single 4'x4' sheet of 3/8" plywood. On the left we have the two front pieces and the back, in the middle is the right and left side, and on the right is the 2 baffles, the top and the baffle spacers. I did not cutout the roof yet, I will explain why down when I actually cut it out.

Before attaching the sides to the back piece I cut out a couple notches for ventilation.

Here I attached the sides and top to the back piece, I left about 1 and 3/8"  space on the bottom to attach the bat house to the tree and the same distance at the top. I pre-drilled pilot holes with a countersink bit and used 1" drywall screws to attach everything.

The next step was to attach the mesh screen, this is a plastic screen door mesh. All of the plans and videos online say to make sure to use the plastic type of mesh not the metal ones. I used my staple gun to secure the mesh and then tapped the staples with my hammer to make sure they were nice and flat.

On either side of the bat house here we have spacers that are 3/4" tall which is the recommended amount of space for the baffles. I used two strips of the plywood to make sure the screws didn't poke through. I just clamped them down and drilled pilot holes and then screwed them in with the same 1" drywall screws. I did have to cut this set of spacers in half to allow for the ventilation. The rest of the spacers are not cut.

Here we have the full length spacers with the first baffle in place. You can see that the baffle has been wrapped all the way around with the mesh. Again I just stapled it down and tapped the staples with my hammer to make sure they were flush. I repeated this same process for the second baffle.

With the second baffle and spacer in place I put mesh on the inside of the front sections and attached them to the sides. I didn't glue or screw either of the baffles in place. In order to secure them I put small spacer blocks at the bottom on either side to stop them from sliding down and out.

From the side here you can see where the roof needs to be attached. Now at this point I hadn't cut the roof piece out. I decided to wait on this because I'm lazy and didn't want to do the math before hand to figure out how long it needed to be. With it put together this far I was able to just stick a piece of scrap wood there and mark it to length.

With the roof piece marked to length I cut it down to size on my table saw and then screwed it down to the side pieces.

Next I ran a bead of weatherproof caulk down the two seams to make sure the bats stay dry inside of the house.

I hung the bat house outside under our deck and gave it 3 coats with a tan exterior spray paint. It didn't coat as well as I would have liked. If I were to do it again I would get regular canned paint and probably prime it then paint it with a brush or small roller.

Below you can see the finished product hanging from a tree in our back yard. I do have some fly paper hanging from the tree below the bat house to try and attract the bats here. It has only been hanging for a few days so I don't know if we have any residents yet.