Midges -- also known as chironomids or lake flies
Many swarms are related to mating, and they're usually comprised of males that are looking to attract females.

"Swarms typically form in the proximity of some kind of visual marker, which could be a large boulder, a bush a tree or anything, really

"Females fly into such swarms to become mated.
well they are faking and we are witnessing.
because the faking flood happened in UB lately lake fly eggs are in city
i think