Cavity nesting birds--those that like hollows for their nests, such as wrens, swallows, bluebirds, and some sparrows---often can’t find a vacant hole in a dead tree, a crack in a building wall, or other natural cavity in which to make their nest. We can provide nest boxes to help. Learn about the kinds of boxes to make and where to put them at https://www.audubon.org/news/build-nest-box-welcome-spring-birds. Spring migrants will soon arrive, ready to nest and raise their babies.