The female might approach several holes that the male has shown her before she enters one. This is an indicator that the two will pair. At this time the female will become dominate over the male. Bluebirds are usually monogamous and pairs may remain together in successful seasons. Copulation begins before nest building and continues into the incubation stage.
Bluebirds are secondary cavity nesters that use the cavity of abandoned woodpecker nests.
Bluebirds will also build their nests in nesting boxes. The building of the nest is done primarily by the female with the male bringing her the nesting materials. Construction of the nest may take from two to twelve days. The nest is built from dried grasses and weeds. Egg laying may not begin for a week or more after the completion of the nest.