They make nests of dry grasses in bird houses or other natural or man-made cavities. This could be a hole in a tree.
Bluebirds sometimes build more than one nest, as a diversion to predators.
They will nest in tree cavities.
Not usually, bluebirds normally nest closer to the ground than martins.
Watch the bluebirds closely to make sure that they incubate them. Also watch out for sparrows and other birds that may crack bluebird eggs or take over the nest.
Yes, you can. They will start over and make a new nest. If you leave it in they will put new materials over the old nest to make it fresh.
Bluebirds spend much of their time foraging for food. When they have babies in the nest, they spend much of their time caring for them.
They can easily fit out the entrance hole.
From March to June. In the south, they nest earlier, and may raise two broods.
Yes, then clean the box.
No. They make a new one for each brood but if you take out the old nest after the young have left the nest they may make a new in that birdhouse.
Never known of a bluebird crawling, it would be difficult..To exclude house sparrows, make the entrance hole around one and a quarter inches across..Also, place the nest box no higher than five feet from the ground, sparrows won't nest so low.
Sometimes bluebirds face competition with other birds over nesting sites. Another problem bluebirds have is a lack of natural habitat. In areas that are more developed there are less natural cavities for them to nest in.