Anyone who has owned livestock will know this inch-long black fighter jet of a fly. Black horse flies (Tabanus atratus) are huge, loud, and persistent attackers of mammals in the females’ quest to get a blood meal in order to reproduce. They fear no swatter. A million years ago, I worked at a wolf sanctuary, and the wolves would look uniformly alarmed when one of these thundered by. Some of the wolves would try to snap them out of the air.
This is a male: black horse flies’ compound eyes are dichoptic (separated) in the female, and holoptic (continuous) in the male, giving him an expensive pair of designer sunglasses.
The females “feed on mammals” for their blood meal, while the males eat nectar. The flies aren’t specifically predisposed to hunt humans, but they will bite, and, if they do, “you will definitely notice”. I’m not sure if they are called horse flies because they feed on horses or because they are the size of horses, but, either way, this photo was taken at 300mm because Hell No.