I thought crows were supposed to be the smart ones of the avian world. Apparently, that's not saying much, as two crows have now spent well over a week attacking the crows in the break room window. It used to be just one crow doing it. I saw him bring a friend over one day, who watched him attack the crow in the window, and then flew off with a distinct air of "You moron!" But our merry attacker has now found a companion for his folie à deux, and the pair have been beating the hell out of the window for a few days.
They're pretty intent on it, too. Just now, when up getting a Coke Zero from the machine, I was able to walk within inches of the window before one flew away, then I stood and watched the other one work for a while before experimentally waving frantically at him to see if he'd notice. He stopped, looked at me for a bit, then flew off. I'm assuming there's a pretty strong reflection on the window there, and maybe we've got some sort of reflective tinting on it. Not worried about them breaking it, as it's double-glazed and strong enough to stand up to mild hailstorms.
But the noises are loud enough that the first day I experienced it, eating in one area of the break room while the crows were busy on a window in the kitchenette area, which is a separate room, I assumed it was workmen back there hammering something. :D