Anyone who’s seen a flock of starlings twist and turn across the sky may have wondered: How do they maneuver in such close formation without colliding?
“Many types of animals swarm or flock or otherwise move in coordinated ways,” says Nicholas Ouellette, associate professor of civil and environmental engineering at Stanford. “No individual animal knows what every other animal is doing, yet somehow they move cohesively as a group.”
Understanding precisely how they do this, Ouellette says, may be a key to helping engineers design “flocks” of aerial drones and driverless cars. Emulating animal swarms is attractive because they not only operate without central control but they’re also fault-tolerant, to use an engineering term, meaning they can adapt quickly and gracefully to sudden or unexpected conditions. Swarms are also resilient in that they can operate in dirty, disturbed environments.
So Ouellette and his team have embarked on a series of studies that explore how animal swarms develop the kind of self-organized and self-regulated systems that would allow devices such as drones and mobile sensors to operate safely and efficiently, without the sort of top-down controls that typify, for example, something like the air traffic control system.
Rather than examine starlings or other birds, which would be impractical to study in the lab because of the space they need to fly, Ouellette and his crew look at non-biting midges, a type of flying insect often found near water or in the shade of trees. Unlike starlings, whose graceful formations, called murmurations, make us stare up at the sky, midges buzz around in chaotic, cloud-like masses. But, says Ouellette, midge swarms still share common features with bird flocks and other animal groups, in that the swarms stay cohesive without any outside control or leadership.
“Midges are so small, they’re easy to keep in a lab,” Ouellette says. “They swarm at dusk and dawn and are easy to cue