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An unmanned aerial vehicle (UAV) is an aircraft without a human pilot onboard. UAVs were first developed in 1849 in Venice by Austrians and were used for military reconnaissance during World War I, including launching aerial torpedoes. Modern UAVs come in various shapes and sizes, ranging from small drones like the MQ-9 Reaper which cost $16.9 million and first flew in 2007, to much larger military drones used for policing dangerous areas and special operations.