Dancing honeybees use democratic process when selecting a new home

In his new book, "Honeybee Democracy," Thomas Seeley, professor of neurobiology and behavior, describes the elaborate decision-making process that honeybees (Apis mellifera) use when they make the life-or-death choice of a new nesting cavity.

When a hive becomes overpopulated, two-thirds of the worker bees and the old queen leave and gather on a nearby branch. Over the next few days, several hundred scout bees search out 10 to 20 potential sites in hollow trees. Meanwhile back at the swarm, each site gets announced with a dance.

"A scout adjusts how long she dances according to the goodness of the site," said Seeley. "She has a built-in ability to judge site quality, and she is honest; if the site is mediocre she won't advertise it strongly."

In turn, other scouts inspect the sites and return to dance for themselves. The best site elicits the most vigorous dances, so its popularity among the scouts grows the fastest. The most popular site is chosen when the number of bees visiting it reaches a critical threshold.

The bee's decision-making process is similar to how neurons work to make decisions in primate brains, Seeley says. In both swarms and brains, no individual bee or neuron has an overview, but with many independent individuals providing different pieces of information the group achieves optimal decision-making. Ants similarly organize themselves to make collective decisions, Seeley said.

"Consistencies like these suggest that there are general principles of organization for building groups far smarter than the smartest individuals in them," Seeley writes.

Humans can learn much about democratic decision-making by looking at bees, Seeley says. If the members of a group have common interests, such as the bees in a swarm, then the keys to good collective decision-making are to ensure the group contains diverse members and an impartial leader -- and conducts open debates.