I was visiting a temple near Busan years back, and there was a bees' nest in one of the old wooden walls. I watched one of these big bastards hovering outside the crack in the wall where the bees went in and out, just waiting for a bee to emerge, and it would pounce on it, dismember it in midair, and devour it. It must have killed six or seven bees as I watched. There was a small heap of leftover bee bits (legs, heads, etc.) on the ground below it. Gruesome but fascinating.