Swallows are adept aerialists, darting to catch flying insects.
They occasionally eat berries and seeds. Flocks perch in long rows on branches and wires. When they nest, they usually produce 2 broods. Male and female build nest in 7 to 14 days on buildings, occasionally caves, culverts and under bridges. Swallows nest in colonies, yearlings from a first clutch often aid in feeding nestlings.