They do almost all of their foraging while in flight. They open up their short bills and use their wide mouths to scoop up insects that are flying by. Usually swallows forage in flocks close to the surface of water or in fields where there are a lot of insects. Some species of swallows nest in colonies and build their nests close together. In this way, there is no territory for the individual birds to defend, except for its own nest.
Swallows migrate south for the winter.
But overall, the group seems to benefit from human structures such as buildings and bridges in which they build their nests. Some species even commonly use birdhouses. The Royal British Columbia Museum. All rights reserved.