Amazon-branded delivery drones may look to us humans like, well, Amazon-branded delivery drones, [however] they look to birds like ... other birds. Encroaching birds. And that's because, as Slate's Nicholas Lund points out, birds—especially predatory raptors, your hawks and your eagles and your harriers—are territorial. Our airspace is also, in a very literal way, birdspace, with birds carving up that soaring territory among themselves, defending their celestial turf against would-be interlopers. Not just with an "excuse me, sir, I think you may be in my seat" ... but with violence. Those dudes will put a bird on it in the most Darwinian way imaginable.