Bank Swallows feed on flying insects. They breed near open habitats along rivers, streams, lakes and gravel pits where they search for flying insects.
Bank Swallows are very social birds. They nest in colonies ranging from 10 nests to nearly 2,000 nests, and they are often found with other individuals when away from the nest.
Bank Swallows typically nest on artificial and natural sites with vertical sand-silt banks such as riverbanks, lake and ocean bluffs, sand/gravel mounds, aggregate quarries and road cuts. Burrows are dug into the sides of these sites; each burrow leads to a nest chamber. Nest burrows are 63 cm (25 in) deep on average and are generally dug straight into the side of the bank (parallel to the ground).
The male Bank Swallow digs a burrow leading to an underground nest chamber using its small beak, feet and wings. The male digs the burrow before he has a mate. The female then chooses a mate and nest by hovering in front of the burrows. The female builds the nest by making a mat of straw, grasses, leaves and roots torn from the exposed bank.