Known as “square-headed wasps,” Ectemnius wasps are elite solitary predators built for aerial hunting. Equipped with massive, boxy heads and keen binocular vision, these agile hunters snatch fast-flying flies—like hoverflies and horseflies—right out of the sky. Once captured, the wasp paralyzes the fly with a sting, keeping it fresh inside a rotten wood nest as a living meal for her developing larvae. Females use powerful, tooth-like jaws to chew through tree stumps and fence posts, creating branched tunnels stocked with up to a dozen flies per room. While each female cares for her own brood, they often share nest entrances in dense groups to save digging energy. I met this impressive hunter on a wide meadow near Akalla, Sweden. At first, I mistook it for a sawfly—a species I frequently see in the same meadow—and managed to snap just one quick photo before it zoomed away!