Bird houses can be set out at any time of the year. However, making them available just before the major nesting season (March-June) will enhance their use.

The following general considerations apply to all bird houses.

• Cleaning - Include a hinged door or other means for easily checking and cleaning out the house. Birds will do their own cleaning as they do in natural cavities, but your help will increase use.

• Drainage - The bottom should contain 3 or 4 1/4-inch holes to allow drainage of rain water that may enter.

• Attachment - Houses built for wrens can be suspended under an eave or a tree limb. All other houses should be firmly attached to a post, tree, or building.

• Perches - Natural cavities do not have perches, so do not attach perches on any built houses. Perches will only encourage use by exotic English sparrows and European starlings. A nail or knife can be used to scratch the outside surface below the entrance if smooth boards are used. Cavity-nesters perch on vertical roughened surfaces such as bark.

• Roof - The front edge of the roof should overhang about 1-2 inches (2.5-5 centimeters) to help protect the entrance from wind-driven rain.

• Ventilation - Ventilation holes or slits should be located at the top of both sides just beneath the roof.

• Nails - Use galvanized nails.

• Floor - The floor should be situated between and about 1/4 inch above the bottom edges of the front, back, and sides. This will help prevent the rain from seeping into the bottom of the nest.

• Wood - 1" x 4", 1" x 6", or 1" x 12", untreated boards are the best materials to use.

• Paint - Newly painted or oiled houses are less attractive to birds until they have weathered. However, it is desirable to paint the top surfaces of purple martin houses white to reflect the sun's heat

• Style - The shape and style of the house are not as important as the dimensions.

• Size - House dimensions should be close to those given in this pamphlet, but they do not have to be exact.