Named for its tendency to nest in human-provided bird houses located near human houses, the house wren is one of our most familiar backyard birds. These hyperactive dark-brown mites sing a rich burbling warble that is a true sign of spring across much of the species’ range, which covers all but the most southern parts of North America. As a cavity nest, house wrens compete with other birds, such as house sparrows, chickadees, titmice, nuthatches, and bluebirds. Despite their small size, house wrens are aggressive competitors for nest boxes, often piercing and ejecting eggs from a nest box. Indeed, bluebird landlords often locate their nest boxes far from woodland edges and human habitation in an attempt to discourage house wrens from taking over the boxes.