While it is okay to paint the outside of a bird house, do not paint the interior surfaces or the inner rim of the entrance hole. Furthermore, use only environmentally safe paints, stains or varnishes on the outside and avoid any lead_based paints that can poison birds from fumes or ingestion. Choose a bird house design with the proper interior dimensions for the desired residents: Too small of a house may cause growing birds to smother, while too large of a house will not be attractive to nesting parents. Smaller birds could also become too chilled in a larger house if they are not huddled together when needed.
Train outdoor pets to keep away from bird houses: Behavioral conditioning with a water hose is an effective method that can also be used on squirrels and other wildlife with enough patience and perseverance. Pets should be supervised when outdoors during the nesting season as well, since young birds leave the nest several days before they can fly, making them easy targets for curious pets. Be sure the bird house opening is the right size for the species you wish to attract: If the opening is too large, predators will have easy access to the nest and other bird species may take over. A very large opening may also be dangerous for growing chicks, which could tumble out of the hole. A small hole could cause birds to get stuck, or they won't use the house at all.