Nuthatches build nests in old woodpecker holes or natural cavities in trees, especially conifers; the red-breasted ones often excavating their own in pines and smearing the edges of the entrances with sticky resin. White-breasteds who are more likely to frequent populated areas will also use a birdhouse or nesting house that you provide. It should have a 4-inch square base and be 10 inches high. An opening only 1¼ inch in diameter near the top will permit wrens and titmice to use the nest box but not sparrows. Omit a perch to discourage predator birds. A house is appealing to nuthatches if its façade is made of bark slabs. Mount it on tree trunk about 12 feet from ground.
Nuthatch couples begin courting as early as January. Males clean out suitable holes and females build nests from bark, feathers, grass, leaves and even squirrel fur. They are likely to use any nesting materials you put out as well. Egg laying commences in March in the South and in April in the North, five to eight brown and lavender speckled white eggs per clutch. Males help with the 12-day incubation and child rearing of the single annual brood. Couples stay together for more than one year. Nuthatches live from 5 to 7 years on average.