Bat Box

Bats are underrated. Besides being the only mammal that flies, most North American bats are nocturnal insectivores, which means they feed on night-flying insects—especially mosquitoes. In fact, a small bat can devour more than 600 mosquitoes in a single hour. They also eat beetles, wasps, and moths. So encouraging bats to nest near your house is a natural way to keep your yard bug-free.

This bat house is easy to make in an afternoon. Its shallow construction is designed specifically to attract bats, which like cramped, dark spaces for nesting. Kids can do lots of the work involved in making this bat house, including measuring, driving screws, and painting. Parents need to help out with the sawing. Once you’ve finished it, hang your bat house high in a sunny corner of your backyard, and the bats will soon find a stylish new home.

Step 1: Overview

Bats are very particular about where they’ll live, and their houses have to be constructed in a specific way that encourages them to nest. The inside of this house is painted black to keep it dark and warm, and the outside is a color that makes it blend in with the surroundings. The space where they go inside the house and roost is only about ¾ inch thick (with a small gap for air circulation). Still, dozens of bats will be able to live in this box and raise their pups.

When working on this project, keep safety in mind at all times. A jigsaw is better off in adult hands, but kids can help out by caulking, driving screws, attaching the netting, and painting. Make sure everyone has safety glasses on when the saw is in use, and keep sleeves away from power tools.

Step 2: Measure and Cut Plywood

Using a tape measure and straightedge, mark up for cutting a 2-by-4-foot piece of ½-inch exterior-grade plywood: You’ll need one piece that’s 2 feet wide and 26 inches long and one that’s 2 feet wide and 22 inches long. Clamp the plywood to a worktable. Make sure you have on safety glasses, then use a jigsaw or a circular 
saw to cut the plywood.

To parents: Using a jigsaw is definitely a job for an adult. But take this opportunity to teach your kids saw safety so they’ll be ready when they’re old enough.

Step 3: Draw the bat design

Print out the template for the bat cutout. Or create your own bat shape using circular and oblong templates called French curves (available at most office supply stores). 
 Lay out the bat shape on the edge of the shorter piece of plywood—just make sure it’s 24 inches wide.

Hey, kids! French curves are great for helping you draw the bat wings, but you can also trace cans or cups to make curves of different sizes.

Step 4: Drill Holes for Jigsaw

Clamp the plywood with the bat design to your worktable, making sure the whole bat hangs over the edge. Using a drill/driver with ¼-inch bit, drill holes just inside the points of the bat shape. This will make it easy to turn your jigsaw blade as you cut out the curved parts.

Step 5: Cut out the bat

Using a jigsaw fitted with a narrow scroll blade, which is designed for making intricate curves, cut out the bat design. Cut the shape closest to the edge first, then cut the whole bat from the sheet. Because both halves of the cutline need to look clean, work slowly and carefully. Whenever you get to a drill hole at one of the points, stop the saw and turn it before you continue.

Step 6: Make the sides

To raise the front panel off the back and create a small crawl space to house the bats, you’ll need strips of lumber around the edges. Cut three pieces from a 1×2: one 24-inch piece and two 19-inch pieces.

Step 7: Attach the sides

Using a caulk gun, lay a bead of caulk along the face of the long 1×2. Line it up with the top edge of the larger piece of plywood, and clamp it in place with spring clamps. Using a drill/driver, drive 1-inch deck screws through the 1×2 and into the plywood every 6 inches to hold it in place.

Attach the two shorter pieces to the sides in the same manner, and caulk the ends where they meet the top piece before you clamp them down. Use a damp rag to wipe up any caulk that oozes out.

Hey, kids! You can help out with the caulking while your parents get the clamps ready.

Step 8: Paint the parts

Using a brush and roller, paint the back piece black, from the top edge to the ends of the 1x2s. Also paint the back of the front piece black. These will form the dark inside of the bat house.

Paint the other surfaces in a color that will help maintain a healthy temperature inside the house. If you live in the North, a dark color can keep the house toasty by absorbing the sunlight. In the warm South, a light color may be a better choice. Be sure all surfaces of the wood are painted and well sealed.

Let the paint dry completely.

Step 9: Attach the netting

Unroll the deer netting, and lay it over the inside of the back section, flat against the plywood. Using a staple gun, attach the netting to the inner edge of the top 1×2 and along the sides. Make sure to pull it taut so that it can’t sag when bats hang from it. Extend the netting all the way over the bottom edge, and wrap it around to the back. Once it’s stapled all around, cut off the excess.

Step 10: Attach the front piece

Caulk along the face of the 1x2s on the back section. Place the front piece onto the 1x2s, with the bat shape facing the bottom, and the top edges and corners lined up. Clamp it in place. Drive 1-inch screws every 6 inches through the face and into the 1x2s to secure it.

Step 11: Put on the bat cut out

Caulk the exposed sections of the 1x2s, then place the cutout onto them, just below the large front piece. Leave a ½-inch gap between the two for the air vent. Clamp the piece, and attach it in place with a single 1-inch screw on each side.

Step 12: Hang it up

Hang your bat house under the eaves of your house or from a tall, flat pole made from pressure-treated lumber. (Make sure to bury one-third of the lumber in the ground to keep it steady.) Attach it by driving 3½-inch deck screws through the corners into the siding or fascia of your house or, if you’re using a pole, along the middle at the top and bottom.

The bat house should be at least 15 feet off the ground, away from bright lights. Choose a place that faces south so that it gets plenty of sunlight (aim for 6 to 10 hours of exposure). This will keep it nice and hot—just the way bats like it!

To parents: Hanging the bat house is a job best left for adults. Just be sure to practice when you put it up.

The original plan can be found at


Bat Box

One of the most surprising changes to have taken place during the last 15 years is the new way many people view the natural world around us, Accelerating deterioration of the environment is making it difficult to deny that the assumptions behind conventional ideas of progress are seriously flawed. Old ideas be reexamined, reworked, and made new. This new view includes seeing the world as an interconnected whole, not just a series of fragmented parts. Bats are creatures we’d be wise to include in this view. Some people say it’s essential that we do. One of these is Dr.Merlin Tuttle.

Concerned about rapidly declining bat populations world-wide, Dr. Tuttle formed the non-profit organization Bat Conservation International (BCI) in 1982, Based in Austin, Texas, and dedicated to the research and promotion of bats as harmless creatures. BCI has compiled a large body of knowledge to support its purpose. Building a bat house for your property is a good first step toward cultivating an understanding and appreciation of
these interesting animals. If this idea scares you, perhaps a few facts will put you at ease.

  1. Bats are mammals. Females usually give birth to and nurse only one pup per year. For this reason, bat populalions grow very slowly and are especially vulnerable 10 devastation.
    2. Bats are not blind. In fact, they have excellent vision and use echo location
    to track down their prey much like dolphins do. They do not get tangled in people’s hair and are no more likely to carry disease than any other wild animal.
    3. The little brown bat (Myotis Iucifagus) and the big brown bat (Epresicus Fuscus)
    are two of the most common species found in Canada. One little brown bat can consume 600 mosquitoes per hour during its nightly feeding flights.
    4. Bats in other parts of the world are essential for pollination of hundreds of
    different kinds of plants (including avacados, bananas, mangos, and peaches) and the dispersal of seeds necessary for the regeneration of the rain forests.
    5. Bats in Canada either hibernate or migrate south during the winter. If awoken by human disturbance while hibernating, one little brown bat will consume enough fat stores to sustain it for 67 days of sleep. Several of these disturbances will kill them.

The bat house design presented here is a of research gathered from several sources and incorporates the latest features intended to appeal to the kind of bats found in Canada. Unfortunately, there’s still a great deal to learn about bats and their housing requirements. For this reason, it’s not possible to guarantee these creatures will move into a house simply because you’ve put it up.

Recent experience shows that bat houses are most effective when placed near buildings containing a nuisance bat population. Blocking up their entry holes after dark can result in the colony moving into the bat house out of necessity. There have also been reports of them moving into houses without being intentionally evicted from neighboring buildings, although this process can sometimes take several years.

Whatever the experience of others, and wherever live, it’s still worthwhile to build a few houses, put them up, and see what happens. If nothing else, they’ll stand as a symbol of your conservation ethic and provide many opportunities to introduce others to the value of these helpful and misunderstood creatures.Over the years, researchers have discovered that the following features should be incorporated into anything you build to attract the kind of bats found in our put of the world:

  • an internal structure of partitions arranged with a 3/4″ space between them
  • Rough, unfinished inner surfaces to allow bats to climb up and around inside the structure
  • A construction style and level of workmanship that leads to warm and dry conditions inside the house

To these three points I’ve added two of my own:

  • a variable width crevice/ledge, My own observation of the little brown bat (most common species in my part of the country) has shown that they can crawl through openings much narrower than 3/4″. They also seem to prefer horizontal ledges at the openings of their favorite crevices. The variable width crevice/ledge found on both sides of the house allows experimentation that may lead to a understanding of what bats prefer
  • the house should be simple to construct and easy to mount on buildings or trees

Fig. 1

Fig. 1 is a cut-away view of the front of the house showing the internal structure of the partitions. These partitions are made of 1/2″ sheathing grade plywood and are the same size and shape as the sides of the house, which are made of 3/4″ pine.
Fig. 2 is an overview of all the required parts, with dimensions and angles. Create everything you’ll need for as many houses as you’d like to build now. Each one will require two sides, six internal dividers, and one each of the front, back, roof. and mounting bracket. To incorporate the variable width crevice/ledge feature, you’ll also need a couple of small strips of pine, also shown in Fig. 3.

Fig. 2

Assembling this project is simple. Use 2 1/2″ ardox finishing to attach the front and back members to one side of the house. Allowing these parts to stick out 1/8″ to 1/4″ beyond the side makes this butt joint look more attractive than if joined flush, (see Fig. 3).

Place the other side member tight against the inside surface of the side you’ve just nailed on, in between the front and back pieces. This second side member will act as a temporary 3/4″ spacer, against which you can place the first of the plywood dividers. Fasten this divider to the front and back pieces with 1 1/2″ finishing nails, four through the front and five through the back of the house. Use a small scrap of wood and a hammer to gently tap out the 3/4″ side piece/spacer from between the plywood divider and the pine side member. Repeat the process by replacing the spacer against the other side by the divider you’ve just installed. Slip another divider between the front and back pieces (tight against the spacer) and nail it in place as you did the first. Repeat the process by removing/replacing the spacer and installing the plywood dividers until all six are in place, each with a 3/4″ space between them.

Since the nails used to fasten these dividers are such a noticeable part of the front Of the house, it’s a good idea to drive them in a straight and regular pattern. Use a square to help you draw faint pencil lines on the front of the house to guide you if necessary. Finish up by installing the second side member (used previously as the spacer) and the roof.

The house featured here has been stained a medium brown color and finished with Sikkens Cetol #1, although a number of other durable products could be used instead. Exterior grade house paint will work well for people who aren’t interested in allowing the natural appearance of the wood to show through in the finished house. Whatever product you choose, it’s wise to finish the house, mounting bracket, and crevice/ledge strips separately in order to protect the wood as completely as possible.

Fig. 3

When you’re ready to install the house, attach the mounting bracket to the back of the house with five #12 x 1 1/2″ screws, countersunk below the surface of the bracket. Since bats prefer warm locations, install the house where it will get as much direct sunshine as possible. A southern or southeastern exposure is very important. Locations 12′ to 16′ off the ground on the side of a building near permanent sources of water seem to work best.

This plan can be originally found at


Bat Box

Build Your Own Bat Box – attract bats to your yard

Did you know that one single bat eats between 6,000 and 8,000 insects PER NIGHT?

Did you know that less than 1% of bats carry rabies (far lower than the incidence in racoons)?

Did you know that a female bat (usually) only has one pup per year?

Did you know that store-bought bat boxes are generally NOT very successful.

Why do I bring this up?

Because this seems like a no-brainer for building/buying and installing a bat box near your home.

Think fewer mosquitoes, natural (and nitrogen-full) fertilizer and aid in pollination all without the risk of them multiplying like mice or bringing rabies to your family pet.

How about this – longer evenings spent outside enjoying your yard without spraying down your kids with toxic chemicals.

Why doesn’t everyone have a bat box?

There are several “Bat Conservation approved” bat box plans available online, but I found them to be a bit brief, so I wanted to share the ‘build your own bat boxes’ I created this past week.

DIY Bat box / DIY bat house

  • 3/4″ outdoor plywood
  • 1 1/2″ galvanized screws
  • outdoor caulking
  • wood glue
  • outdoor paint
  • outdoor varnish/polyurethane


  • 18 x 24″ for backing (18 x 26″ would be even better, but 24″ will work)
  • 18 x 12″ for front upper
  • 18 x 6″ for front lower
  • 2 pieces at 18 x 1 1/2″ for sides
  • 16 x 1 1/2″ for inner roof
  • 18 x 3/4″ for protective ledge
  • 18 1/2 by 4″ for roof (cut at a 30 degree angle along one long edge)

Bats need a way to climb up into, and roost, inside your bat box.  The easiest, and most cost effective way I found was to create a ladder along the inside of your box:

Start by setting your table saw blade height to 1/4″ (or less) high and cut notches in your bat box back at every half inch.

This may seem tedious, but you can notch one side, turn the board around and notch the other end without moving your guide rail – so two cuts from each measurement.  To notch my entire back it took 15 minutes, and that’s with taking photos as well.

Alternatively, you could cut and staple plastic mesh to your back board, but I have read where the staples will rust and the plastic will bow over time, making your house less appealing to bats.

Next you’ll need to attach your sides;  I made mistakes on both bat boxes that I built in that I didn’t leave enough space for my outer roof and mounting holes on the first one.  I’ll still be able to hang it with L-brackets, but leaving space above the side beams would have been better.

Glue your side pieces to your backing leaving a 4 – 5″ gap from the bottom and a 3 – 4″ gap from the top (adjust accordingly to fit).  Screw into place, from the back,  with your 1 1/2″ galvanized screws.

Next glue down your inner roof piece between the sides and screw into place (from the back).

Your box should look approximately like this:

From what I’ve read, bats require a lot of heat – and it was recommended that bat boxes be sealed with caulking to keep the heat in and the weather out.  I found the caulking to have a really strong smell and I questioned whether they’d roost here or not, but after checking several sites, they all say the same thing – seal it tightly.

Before attaching your top plates, run another strip of caulking along the side and inner roof pieces and press tightly.  Screw into place using 1 1/2″ galvanized screws while the caulking is still wet (it will give it a better seal).

Line your front upper along the inner roof piece and screw down from the front.

Before attaching your front lower piece, leave an opening between the boards that is 1/4″ to 1/2″ for ventilation.

This will give you a small overhang at the bottom of your box.  Here you’ll attach your protective ledge.  It’s just a little extra protection from predators.

You can nail or screw this into place.  Don’t worry about caulking this section.

Finally, line up your outer roof piece so that the 30 degree angle is flush with your backing and there is an overhang on the front of your box (mistake number two – my roof wasn’t wide enough so I had to add another row of caulking to seal the weather out).

I purchased a new-to-me scroll saw earlier this week and was itching to try it out and what better beginner project than a simple bat.

If I were to make a third bat box, I’d correct my other two mistakes AND paint the entire box before adhering the decorative batn- but I’m a “learned the hard way” kind of gal, so painting around the bat was the route I was destined to take.

You could leave your bat box plain – with just an outdoor sealer/varnish to protect it – but it is highly recommended that you paint your box to help attract sunlight and therefore heat.

For my area, black was the recommended colour.  One coat of outdoor paint and a coat of triple-thick outdoor varnish and my build your own bat box / DIY bat box is done!

Your bat box will need to be between 15 and 20 feet off of the ground in a cleared area – they need to have a clear path to take off from and to land, so a tree’d space won’t find much success.

Your bat box will need about 7 hours of morning sun in order for them to want to move in.  They are mammals and like to be toasty warm after a long night’s work (don’t we all?).

Mother bats tend to look for roosts in April (depending on your location) so putting up your bat box in the Fall will give you a better chance of it being used come Spring.

My thoughts are 1.  who wants to be out in freezing cold April to put one of these suckers up and 2.  putting it up now will give it time to weather and get rid of the strong scents of caulking and paint – but that’s just my two cents.


The original plan can be found at