Adults have a forked tail. Adult males are a glossy dark purple. Adult females are dark on top with some purple on the back and lighter underneath.
Their breeding habitat is open areas across eastern North America, also some locations on the west coast from British Columbia to Mexico. They mainly nest in man-made bird houses, also in tree holes or other cavities, typically in colonies. They are more likely to nest in natural locations in the west.
These birds hunt for insects in flight, although sometimes they will pick up insects off the ground. They usually fly relatively high, so, contrary to popular opinion, mosquitos do not form a large part of their diet.
