In the 1970s the CIA built a dragonfly-shaped micro-drone called the 'insectothopter' to carry a tiny listening device — long before hobby drones existed.

The gadget was a genuine attempt at a miniature unmanned aircraft disguised as an insect, powered by a tiny gas engine. It reportedly flew but proved almost impossible to control in wind, and the concept was shelved — decades ahead of the palm-sized drones that are now commonplace.