Wrens are typically small, brown and very cautious. They prefer to raise their young in crevices and nooks that lie outside the reach of predators. But that doesn’t mean avid bird-lovers can’t create an inviting atmosphere that will attract them. You can build a wren house in your own backyard with a few simple supplies that will bring them close enough for you to observe them.
Mark the board, starting at one end and working down the length of the board to the other end. Measure 11 inches for the back, 8 inches for the front, 8 1/4 inches for the roof, two sides measuring 8 inches each and 4 inches for the floor. There will be a small piece left over at the end of the board after you have marked all of your pieces.
Cut out the pieces of the wren house. All of the pieces will be the same length when you are finished, but varying widths.
Drill a 1 1/8-inch hole in the front section, centering it with both sides and placing it 1 inch from the top. Drill 1/4-inch holes in each of the four corners of the floor for drainage and the two top corners of both sides for ventilation. Place these ventilation holes about 1 inch from the edges so they won't be covered when you assemble your wren house.
Put your wren house together. Stand one of the sides up long-ways and place the back on top of it with the sides flush. Leave 2 inches at the top and 1 inch at the bottom when positioning the sides onto the back. Apply wood glue to the seam and hammer a nail in each end, then turn the house on its side to attach the front in the same manner. You will attach the other side later.
Slide the floor up in place between the one side and the front. Glue and nail it into place. Apply the roof with glue and nails, allowing the front to hang over by about 1/4-inch.
Attach the last side in such a way that you can swing it open to clean the inside of the house. Don't use glue when you attach this side. Nail the tops of the side to the front and back of the house. Use a screw to secure one side of the bottom. This screw is easily removed when you get ready to open the side for cleaning.
Place your wren house 6 to 10 feet above the ground by nailing it in place. If you have more than one house, space them at least 20 feet apart and clean them out after the nesting season is over.
Use wood for your wren house because it's cooler, dries out more quickly and is less likely to develop mold and mildew. Fir, white pine, cedar or cypress are the best choices. Wrens arrive about mid-April and usually lay 6 to 8 eggs, which incubate for 15 days. The young birds are ready to fly when they are about 15 days old. A wren may have two broods a year, but rarely uses the same house for her second one.
Never use lead-based paint on your wren house. Never use treated wood to build your wren house. The entry hole shouldn't be any larger than 1 1/8-inches as other larger, more aggressive birds might take over the house.