Introduction: The Bat House: a Green, Energy Efficient Insect Repellant

About: I'm a Coral Reef Ecologist with a passion for photography. Check out my latest project at
It's summer, and you know what that abundance of nature's flying vermin--mosquitos! 

Instead of buying a bug zapper, try building a GREEN, ENERGY EFFICIENT alternative: a bat house!

Bats are mother nature's insecticide, and a single brown bat can eat up to 1,000 mosquitos an hour! ( Additionally, bats are an essential part of a healthy ecosystem, and their populations have diminished in recent times due to deforestation and loss of habitat. Lastly, bats are just cool. 

Bat houses come in a myriad of shapes and sizes, but I decided to build the most simple version I could find. This is a Single Chamber bat house, and can hold up to 50 bats. This design was based off of the plans from (link above), and I need to give credit to good friends of mine, the Warren clan for inspiring me to build one, and for tips and advice.

Step 1: Supplies and Materials

This is a fairly simple build, but you will need some hardware: 

The size of your bat house can vary, depending on the amount of wood you have available. Use these measurements as an approximation if your supplies are lacking. 
  • 1/2'' or 3/4'' outdoor grade plywood (or whatever you have)
    • 26.5'' x 24'' -- the backboard
    • 16.5'' x 24''
    • 5'' x 24'' 
    • 1'' x 21.5'' (two)
    • 1'' x 22'' 
  • 1'' screws
  • exterior (water based!) staining or sealant 
  • caulk
  • black spray paint and tape (optional-for decaling)
  • shingles, galvanized metal sheet, or left over wood for a roof (optional)
  • saw
    • miter saw
    • table saw
    • hand saw (if don't have a miter saw or table saw)

Step 2: Step 1: Cut the Wood

1. Using a table saw, cut your 1/2'' or 3/4'' outdoor grade plywood: 
  • 26.5'' x 24'' -- the backboard
  • 16.5'' x 24''
  • 5'' x 24''
Then cut the furring strips:
  • 1'' x 21.5'' (two)
  • 1'' x 22''

2. Then, saw grooves throughout the full length of  the backboard- this gives the bats something to grip, climb, and hang from in the bat house. The easiest way to do this is with a miter saw, but if you don't have one (I didn't) you can use a table saw- simply lower the saw height to about 1/4'' and saw lines across the board. If you don't have a table saw, you could do this with a handsaw or dremmel (warning- this is quite tedious). 

Step 3: Step 2: Paint/ Seal the Wood

Apply the wood sealant or stain to the interior of the backboard and outsides of all the pieces. 

Step 4: Step 3: Assemble the House

Attach the furring strips to the outer rim of the backboard with caulk. 

Then attach the front top and bottom piece on top with caulk. Leave a 1/2'' vent in between the top and bottom front piece. 

Then use screws to secure the pieces together. 

Step 5: Step 4: Put a Roof Over Their Little Heads

This is optional, but highly recommended. 

You can use shingles, galvanized metal, or left over wood to create a roof for the house. 

I simply used some left over pieces and cut the wood at a 45 degree angle for a roof. 

Step 6: Step 5: Tag It

This is also optional, and just as highly recommended. 

Make a paper stencil, cut it out, and trace it on some tape on the house. Cut out the stencil, and paint away.

Step 7: Step 6: Hang It

Using long nails or screws, mount the bat house. According to the National Wildlife Federation, the ideal location is about 10-15ft high, with a clear area below, free from branches, etc.

Also, NWF says bat houses mounted on poles or on the side of buildings are easier for bats to locate. 

Also, houses should ideally face southeast, to catch some sunlight during mornings to warm their little bat bodies up.

I mounted mine on tree, but may move it to a pole soon. It can take up to a year or so for bats to take refuge in your house. But once they do, you'll have these friendly, cuddly little minions to do your bidding. 

I hope you found this Instructable useful, and if you like it, please vote for me in the GREEN TECH Contest by clicking "vote" !