The drone, built by AeroVironment with funding from DARPA, is able to fly forwards, backwards, and sideways, as well as rotate clockwise and counterclockwise. Not only does the 'bot resemble its avian inspiration in size (it's only slightly larger than a hummingbird, with a 6.5-inch wingspan and a weight of 19 grams), it also looks impressively like a hummingbird in flight. That's not vanity--it's key to the drone's use as a spy device, as it can perch near its subject without alerting it (supposing that area has a population of hummingbirds--the usual reaction to seeing a hummingbird here in midtown Manhattan is something like "OMG you guys look at the hummingbird!!!!!!," which is not necessarily an ideal situation for a spy-drone).