If you would build a castle in the air, build a bird house. Birds are airy creatures so they must have their houses In the air. Whether it is a small log cabin among the vines on the back porch, a half cocoanut shell near the eaves outside the bedroom window, a many porched and windowed affair perched on top of a pole in the garden, or a swinging twig house hanging from a tree, it should be made attractive to both the bird dwellers and the good people who put it there.