This system – dubbed the ant colony optimization method – has actually been turned into an algorithm for improving human scheduling, telecommunications, transport and logistics across the world. Experts have used ant optimisation algorithms for railway planning, for instance, and Dorigo developed AntNET, a system to efficiently move information around within communication networks.
Democratic honeybees
Honeybees use a method very similar to ants’ optimized foraging when it comes to finding their new nesting spot.
Several scout bees fly out and look for options at random, like ants. But instead of leaving trails of pheromones, they come back to the nest and directly communicate their preferences. They do a waggle dance for their nest mates, rhythmically shaking their bodies to convey whether they think the new site has what it takes: how safe it is, how close, how large, how well-positioned. The better the nest site, the longer and more vigorous the dancing.
The waggle dance also describes the exact location – how far to go and in what direction the nest mates need to fly – and another round of bees is then sent out to corroborate these findings. When they return with they give their verdict in dance, too, either supporting their predecessors or offering new options.
Over time, a preferred location naturally emerges: a couple of dozen bees return from their expedition with positive dances for the same place. They reach a quorum, and they move accordingly from there, like in a human democracy.
Neutral locusts
Getting people to change their minds is hard, especially when a group is split between two options. The debate can quickly descend into a stark black-or-white binary, leaving everyone feeling even more entrenched in their ways.
Fortunately, a recent study on locusts points to a way out of this common bind.
Marching locusts are locusts so juvenile they still don’t know how to fly, so they march instead. In his experiment, Christian (Kit) Yates, professor of mathematical biology at the University of Bath, UK, put groups of them in a ring-shaped arena to observe how they collectively decide which direction to go. He realized they routinely flip-flop direction, after a moment of stalling.
It turns out that it is this fleeting moment of suspension – when more and more locusts stop marching and become neutral – that helps the swarm break out of one consensus and switch to the other.
In the experiment, Yates also tested 19 humans with a similar task: he ran a game where participants could choose between X and Y, or abstain. Like the locusts, they found that when people had the option to abstain, it helped the group reach a consensus – just X or just Y – more “quickly and cleanly” than when they didn’t, says Yates.
