Swallows are songbirds best known for their uniquely shaped tail feathers but not all swallows have the split tail. Those that do split into 2 forks with longer feathers on the edges. Swallows are members of the family Hirundinidae.

Swallows are well known as prodigious insect eaters and acrobatic flyers. They combine these 2 attributes as they catch insects while on wing. This means they swoop and dive and make turns on a dime.

Another fun fact about swallows is that they share a close association to humans. Barn Swallows can live elsewhere but seem to prefer big old barns or other buildings with open doors and rough jousts as nesting sites. Purple martins (a type of swallow) are, almost if not totally, dependent on man made housing in North America. They live in colonies and loyally return to their same “apartments” each year. You may have observed large birdhouses on tall flag poles with multiple birdie apartments or clusters of gourds suspended from trees which are meant to attract Purple Martins. Puple Martins prefer to nest in colonies. Slightly older birds lead the way for the younger crowd.

When I mowed my lawn today I was accompanied by about 6 swallows, I think they were purple martins. They swooped down just in front of the mower, grabbed a fleeing insect on wing and swirled away, only to return in moments. It was amazing. I've never seen them up close before. They are so beautiful. A purple martin house will be on my birthday wish list this year.
I've realized these were some other type of swallow, not purple martins as they have light bellies with some orange tinge. Purple Martins are the only swallow that is totally dark featured throughout. I think my swallows must be either barn swallows or tree swallows, as there are plenty of both barns and trees around here.
"My" swallows must have been migrating, they stuck around a few weeks then we didn't see them again.