Area 51's Robotic Spy Bird

Those robo-dragonflies may not be the only creatures keeping an eye on you. For many years now intelligence agencies have been looking at drones disguised as birds. These days flapping-wing 'ornithopters' are not easy to tell apart from birds – take a look at this video of a robo-peregrine and some seagulls and see how long it takes you to spot the impostor.

http://blog.wired.com/defense/2007/11/its-a-bird---it.html