One of the most common swallows in urban environments, it measures between 12 to 13 centimeters. It has white feathers from the beak to the belly, while the wings and tail are black. The plumage of the back is a very dark blue, which can only be detected in good light. It is usually seen flying with ease in large flocks, always looking for insects. It has the habit of building nests in human constructions, in cracks and roofs. Flocks of small-house swallows can be seen flying in the skies of the Campus of Praia Vermelha and occasionally perched on high voltage wires.