Snags provide ideal feeding sites for woodpeckers as many insects live and reproduce in decaying wood. Many snags are covered with small holes made by foraging woodpeckers. Though woodpeckers have powerful bills and neck muscles, they are only able to excavate nests in trees with soft decaying centers. Thus, dead or dying trees are preferred excavation sites. Unlike most other cavity_nesting birds, woodpeckers rarely use birdhouses. 22
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.