We enjoy the acrobatics of barn swallows as we walk along the lakeshore in Michigan. These birds and the dragonfly are are friendly insect catchers. We sit on a breakwater or at a bench and watch them dive and swoon capturing insects.
I do know the barn swallows can make a mess beneath their nests. It is possible to provide them with a conducive environment where they build in places where their droppings are a part of nature.
They are so small and so fast! They can change direction unexpectedly. But they aren't afraid of us sitting and chatting, so they come very close, possibly because of the insects attracted to us. Photographing them in flight can be a challenge!
Original material: https://roadtrek210.blogspot.com/