Jonathan Beard, contributor
In spring, a bee colony's thoughts turn to swarming. The queen and about two-thirds of the workers leave their hive to search for a new home.
The swarm perches on a nearby tree, then sends out a few dozen scout bees to scour the neighbourhood. Their job is to find, measure and evaluate every hollow tree or other enclosed space. When the scouts return to the several-thousand-strong swarm, they dance atop the other bees, telling them what they have found.
A potential nest must be large enough to hold ample honey to feed the colony through the winter, high enough to offer protection from predators, and have a small entrance for the same reason. The vigour and duration of each scout's dance reflect her enthusiasm for the site she has found.
We understand how all this works thanks to Tom Seeley, a Cornell University entomologist who has devoted almost 30 years to studying the "house-hunting" behaviour of honeybees. In Honeybee Democracy, Seeley carefully narrates his many seasons of experiments using plywood nest boxes that could be moved and modified at will. He discovered what bees like in a home, how scouts measure the dark interiors of these boxes and, most of all, how the swarm "votes" to decide which nest to occupy.
Once Seeley and his colleagues knew what size box, in which location, would constitute the best future nest, they set out a variety of boxes on an island, and let swarms choose. They consistently chose the best site. He knows from years of observation that, in the wild, most swarms die over the winter because they are not able to find a suitable home.
The decision-making process, he says, is both effective and efficient, involving a "debate" over the several sites the scouts discover. When a scout returns and dances vigorously, other scouts fly off to check on her choice. Over the course of hours or days, they reach a consensus, and advocates of rejected sites simply stop plumping for them.
This selfless process works because all the bees in the swarm are the queen's daughters, and they share the common goal of colony survival. Though an individual bee is not particularly intelligent, the collective "swarm intelligence" produces impressive results.
Honeybee Democracy is a brilliant display of science at work, with each experiment explained and illustrated. It is only at the end, when Seeley tries to introduce honeybee democracy at departmental meetings at Cornell, that his persuasive book falters. Humans are different: we are not all siblings, we rely on leaders, and we make choices for selfish reasons.
by Thomas D. Seeley
Princeton University Press