Unmanned aerial vehicles (UAVs) first sprang from the fevered imagination of radio-control inventor Nikola Tesla, but it would take a few world wars before the United States military produced some of its own. They were but poor cousins of the missile-packing Predator and Reaper drones used in 21st-century Iraq and Afghanistan. Despite dropping to their lowest levels in half a decade, drone strikes drew a firestorm of media attention in 2013, due to a combination of vocal advocacy groups, news leaks and a global groundswell of citizen concern over civilian casualties and the possibility of terrorist organizations using them as a recruitment tool [source: Walsh].
Meanwhile, UAV development soared to new heights. BAE Systems announced its Taranis supersonic drone, which can blow past the Predator (135 mph or 217 kph) and Reaper (300 mph or 483 kph) [source: Popular Science]. On a smaller scale, AeroVironment debuted the Puma AE, a hand-launched, fixed-wing UAV equipped with a 360-degree camera, laser illuminator and infrared night vision, while Prox Dynamics deployed a 35-ounce (992-gram) hand-held chopper drone. Elsewhere, work is underway on developing insect-and-bird-sized drones featuring flight dynamics taken from the natural world [sources: AeroVironment; Bumiller and Shanker; Prox Dynamics].
In the U.S., sheriffs tested UAVs as a means of patrolling for illegal border crossers, lost hikers and criminals [source: Horgan]. So, as the UFO enthusiasts say, keep watching the skies.