To build the best bird house, you first need to learn what cavity_nesting birds are frequent visitors in your region. These are the birds most likely to investigate your house, and when you keep their needs in mind, you can build a bird house to invite them to become more permanent residents. Start With a Plan: A bird house doesn't need to be complicated, but if you haven't built one before, it is best to start with a tried_and_true plan. There are many free bird house plans available online with styles and designs suitable for beginning woodworkers to experienced architects, or you can buy a book of bird house plans for a hard copy reference.
Snags with old woodpecker holes provide homes for swallows, chickadees, nuthatches, bluebirds, owls, and other cavity_nesting birds that are rarely able to excavate their own nest sites. Snags provide ideal hunting perches for Red_tailed and Rough_legged Hawks, Bald Eagles, Hawk Owls, Great_horned Owls, and other raptors. Snags provide "songposts" to a wide variety of birds. Many small birds use songposts sticking above other vegetation to sing (to attract mates and proclaim nesting territory boundaries) and to perch on when looking out for predators and/or other birds.