Barn Swallows use open areas like breezeways, barns, docks or bridges to build their grass and feather lined mud nests. Originally, these swallows nested in caves and on rocky cliffs. But they quickly adapted to man-made structures.
The above image of Barn Swallow fledglings was taken in late August. After the fledglings fledged, all of them returned to the breezeway every night for a week before heading south as a family.
Swallows are known for their appetite for insects and should be encouraged to to live in your backyard wildlife habitat. If you don't have a barn or swallow-friendly structure, you can purchase imitation swallow cups to hang from the eaves of your house.