A group of swallows is commonly called a Flight. Other collective nouns you may see include Gulp and Kettle.
A collective noun for swallows can be referred to as a flock. Flocks of swallows are mesmerizing sights, showcasing the remarkable flight agility and synchronized movements of these graceful birds. They often gather during migratory periods, forming expansive formations that dart and glide through the air with seamless coordination. Flocks comprise numerous swallows intertwining their flight patterns, often creating captivating aerial displays. These tightly knit communities of swallows pledge to socialize, roosting, nesting, and feeding together, encapsulating the essence of unity and cooperation within their collective existence. Emanating energy and enthusiasm, these flocks of swallows exemplify the marvels of nature's communal spirit and inspire awe among spectactors fortunate enough to witness their mesmerizing ballet in the sky.
Known collective nouns for Swallows include: