A robot hummingbird is the military's latest flying spy machine, with a camera affixed to a featherweight 6.5-inch body that flies by flapping its wings. The "Nano Hummingbird" can fly just 11 miles per hour and stay in the air for only eight to 11 minutes; DARPA paid AeroVironment $4 million for it. But that's a small price to pay for the ability to fly through doors to spy on people without them noticing. Right?

Via: Discover