Things You'll Need
- Tape measure or ruler
- Pencil
- Bird-safe wood board
- Handsaw or circular saw
- Keyhole saw or jig saw
- Sandpaper
- 1 1/2-inch hole saw
- Waterproof wood glue
- Razor
Instructions
Measure the diameter of the preexisting entrance hole to your birdhouse with a tape measure or ruler.
Use a pencil to draw a square the same size as the entrance hole measured in step 1 on a small bird-safe wood board, such as pine or Manzanita wood.
Align a handsaw or a circular saw just outside of the pencil marks on the board to avoid cutting too small. Cut the wood.
Draw a circle inside the square board; it should touch all four sides of the square. Round the square with a keyhole saw or jig saw to create a circle.
Lightly sand the outside of the circle if it does not fit perfectly in the preexisting birdhouse entrance.
Locate the center of the circle from step 4. Cut a 1 1/2-inch hole in the middle circle with your hole saw.
Attach the resized hole to the preexisting entrance with waterproof wood glue.
Remove any residual wood glue with a razorblade once it has dried. Paint the resized entrance to match your birdhouse if desired.