Honeybee Democracy - Thomas D. Seeley (2010)


Sixty years ago, Martin Lindauer happened upon a beardlike cluster of honeybees hanging on a bush and noticed something odd: the handful of bees on the swarm that were waggle dancing were black with soot, red with brick dust, and gray with soil. Why were they so grubby? Could it be, he wondered, that while most of the swarm bees had been quietly bivouacked in the bush, these dirty dancers had been out searching for nest sites? With this chance observation, and the insight it sparked, Lindauer embarked on what he would later describe as “the most beautiful experience” of his life: probing the mystery of how a honeybee swarm finds a home.

This book has reviewed how Lindauer and his scientific successors have solved the mystery of how a bunch of bees can wisely choose their new residence. We have seen that this decision is made by a search committee composed of a few hundred scout bees, all of whom have previous experience as foragers but have switched to exploring dark cavities instead of visiting bright blossoms. And we have seen how these house hunters search for candidate dwelling places, share their findings by performing dances, conduct an extended debate about which one is best, and eventually come to an agreement about the swarm’s new home. Almost always, the collective wisdom of the scout bees chooses the best available option, so that the swarm occupies a nest cavity that provides good protection and sufficient space to hold the large honey stores that the colony will consume in keeping itself warm throughout winter.

We now know that the amazing feat of democratic decision making performed by the scout bees offers us deep lessons about how a group of individuals with common interests can structure their group so that it functions as an effective decision-making body. It is worth taking careful note of how the scout bees man age to be so good at all three of the key ingredients of good decision making by a group: identifying a diverse set of options, sharing freely the information about these options, and aggregating this information to choose the best option.

Remarkably, the scout bees do all these things without working under the guidance of a leader. Doing so certainly steers the bees clear of one of the greatest pitfalls to good group decision making: a dominating leader who advocates a particular outcome and thereby inhibits the group from taking a broad and deep look at its options. But the absence of a leader among the scout bees also means that they operate without the benefit of someone in charge to state the group’s objectives, define the group’s methods of deciding, keep the group on track during its meeting, foster a balanced discussion among the group’s members, and identify when a decision has been reached. The scout bees in a swarm are able to work together well without supervision partly because each bee has a strong incentive to make a good decision; their swarm’s survival depends on the scouts finding it a suitably secure and roomy place to live. The success of the leaderless scout bees is also favored by the reality that they have just one problem to solve (so there is no confusion about their objective and no tendency for their discussion to drift off topic) and by the way they have rules of procedure that are hardwired into their nervous systems (so there is no need for someone to define or enforce their rules of procedure). Thus the house-hunting bees remind us that the leader in a democratic group serves mainly to shape the process, not the product, of the group’s deliberations. The bees also demonstrate that a democratic group can function perfectly well without a leader if the group’s members agree on the problems they face and on the protocol they will use to make their decisions.

The first challenge faced by every decision-making assembly is to identify the available options. Ideally, its members will uncover all the relevant possibilities. We have seen that the house-hunting scout bees approach this ideal by searching widely for prospective nesting sites and discovering a few dozen candidate home-sites. The bees’ success in finding a broad range of options refects two things. First, they are a large group, usually several hundred individuals, so they bring considerable bee power to the search for possible places to live. Second, they are a diverse team of explorers, with no two individuals probing the exact same region of the surrounding countryside. For example, one bee will fly of in one direction and examine the dusty knotholes that she finds in the trees on a certain hillside, meanwhile her fellow scouts will set out in various other directions and inspect the cracks in buildings, abandoned woodpecker nests, and whatever other possibilities they encounter. The differences in where the scout bees explore for future accommodations may refect differences in where they previously worked as foragers, differences in their “personalities” (some may prefer to search far out while others may wish to hunt near by), or differences in combinations of these and other factors. Whatever the exact cause of the variance in where the scouts conduct their reconnaissance, the result is that they discover a broad assortment of possible living quarters. This variety makes it likely that at least one of their finds will provide the bees with an excellent home.

Besides doing a good job of uncovering options, the members of a decision-making group must also do a good job of sharing the news of their finds. If an individual doesn’t make the news of her discovery public, but instead keeps it private, this information will go unused, and this can lead to an inferior decision by the group. Imagine, for example, someone in a group uncovering a first-rate option but then not revealing it to others; the group cannot incorporate this information in their discussion. Given the critical importance of exposing all private information that is relevant to a group’s decision making, it is not surprising that when a scout bee in a honeybee swarm locates a potential nesting site, scrutinizes it, and concludes that it has high value, she quickly flies back to the swarm cluster and excitedly announces her discovery. We have seen that she does so by performing a waggle dance that reveals the direction, distance, and desirability of her find. The more highly the little scout bee values her property, the more dance circuits she performs, and the more as-yet-uncommitted scout bees she attracts to her site. We have also seen that the scouts who make the original discoveries of potential home-sites tend to announce their finds especially persistently, probably to help ensure that the information that they alone (at first) possess gets passed to others and so becomes part of their swarm’s pool of public information. It should be noted too that every scout bee is free to advocate whatever site she finds, even one that is a relatively poor option. In a sense, then, on a honeybee swarm, all views are welcomed and respected; all opinions may be voiced.

Once a decision-making group has gathered and shared the information about options, it next faces the challenge of aggregating this information to choose a winner. We have seen that the bees do so in a most ingenious way, by conducting a frank debate among the scout bees supporting the various proposed nest sites. This debate works much like a political election, for there are multiple candidates (nest sites), competing advertisements (waggle dances) for the different candidates, individuals who are committed to one or another candidate (scouts supporting a site), and a pool of neutral voters (scouts not yet committed to a site). Also, the supporters for each site can become apathetic and rejoin the pool of neutral voters. The election’s outcome is biased strongly in favor of the best site because this site’s supporters will produce the strongest dance advertisements and so will gain converts the most rapidly, and because the best site’s supporters will revert to neutral-voter status the most slowly. Ultimately, the bees supporting one of the sites—usually the best one—dominate the competition so completely that every scout bee supports just one site. A unanimous agreement is reached. It is important to note that even though the scout bees’ way of making a decision ends with a consensus, the bees do not minimize conflict to reach this consensus. Specifically, there is no suppression of dissenting views in the debate. Moreover, there is no pressure toward social conformity. Instead, each scout bee makes her own, independent decision of whether or not to support a site, based on her own, personal evaluation of the site, not on how others judge the site. Thus the bees aggregate the information about their options by conducting an open debate in which the best site prevails by virtue of its superiority, as judged time and time and time again by dozens, if not hundreds, of independent-minded scout bees.

For millions of years, the scout bees on honeybee swarms have faced the task of selecting proper homes for their colonies. Over this vast stretch of evolutionary time, natural selection has structured these insect search committees so that they make the best possible decisions. Now, at last, we humans have the pleasure of knowing how this ingenious selection process works, and the opportunity to use this knowledge to improve our own lives. Some have said that honeybees are messengers sent by the gods to show us how we ought to live: in sweetness and in beauty and in peacefulness. Whether or not this is true, I believe that the story of house hunting by honeybees can inspire the light of amazement about these beautiful little creatures, a light that I hope has shined through each page of this book.