Ed Yong in Not Exactly Rocket Science:
In a field outside Budapest, Hungary, ten quadcopter drones are flying as a coordinated flock. They zip through the great outdoors, fly in formation, or even follow a leader.
The little machines are the work of Hungarian scientists led by physicist Tamas Vicsek from Eotvos University in Budapest. They’re autonomous, meaning that they compute their flight plans on their own, without any central control. They can follow instructions, but they work out their own paths using GPS signals to navigate and radio signals to talk to one another. They’re the closest thing we have to an artificial flock of birds.
The copter flock is a real-life version of an influential computer programme called Boids, created by Craig Reynolds in 1986. He programmed virtual flying objects—the eponymous Boids—to move according to three simple rules. They aligned with the average heading of their neighbours; they were attracted to each other; and they also repulsedeach other to keep some personal space. These three simple rules were enough to simulate a realistic bird-like flock.