Monrovia-based Aerovironment reports this morning that it has reached a technical milestone, and has demonstrated a prototype of a "hummingbird-like" nano air vehicle for a Defense Advanced Research Projects Agency (DARPA) contract. The firm said its two-wing, flapping aircraft was developed to meet a milestone in part of a DARPA Phase II contract, aimed at developing unmanned nano-sized aircraft. The firm said its vehicle weighs two-thirds of an ounce, including batteries and a video camera, and is capable of climbing and descending vertically, flying sideways right and left, forward and backwards, and can be remotely controlled.