The most important thing to consider when buying a bird house is to simulate what cavity-nesting birds would typically use in nature. Birds are concerned with location, direction the hole faces, inside dimensions and probably most important, the size of the opening. We only sell houses that meet the standards for cavity nesting birds that have been set by the ornithological community through years of scientific research. Even if a house we sell is highly decorative, we strive to make sure the basic needs of the birds are met by the design.
Eastern Bluebird houses feature a 1 & 1/2 inch hole