Woodpecker Houses are a way to save your trees and even your house. Wood peckers are cavity nesters. When you buy a woodpecker house, make sure for downey woodpeckers that the opening is 1.25" and for red-bellied woodpeckers, red headed woodpeckers and yellow fronted woodpeckers, the opening is 2". You can attract these woodpeckers with sunflower seeds, corn and nuts. They are very fond of fruit, too.