DARPA contributed $4 million to AeroVironment since 2006[4] to create a prototype "hummingbird-like" aircraft for the Nano Air Vehicle (NAV) program.[5] The result was called the Nano Hummingbird which can fly at and move in three axes of motion. The aircraft can climb and descend vertically; fly sideways left and right; forward and backward; rotate clockwise and counter-clockwise; and hover in mid-air. The artificial hummingbird maneuvers using its flapping wings for propulsion and attitude control. It has a body shaped like a real hummingbird, a wingspan of, and a total flying weight of —less than an AA battery. This includes the systems required for flight: batteries, motors, and communications systems; as well as the video camera payload.
DARPA established flight test milestones for the Hummingbird to achieve and the finished prototype met all of them, and even exceeded some of these objectives:The device is bigger and heavier than a typical real hummingbird, but is smaller and lighter than the largest hummingbird varieties. It could be deployed to perform reconnaissance and surveillance in urban environments or on battlefields, and might perch on windowsills or power lines, or enter buildings to observe its surroundings, relaying camera views back to its operator. According to DARPA,the Nano Air Vehicle's configuration will "provide the warfighter with unprecedented capability for urban mission operations."