Bees balance the needs of timeliness and accuracy when finding a new home. Of a swarm of 10,000 bees, about 200-500 of the elder worker bees (2-5%) scout possible sites over about 30 square kilometers. About 25 bees might find a potentially suitable new site.
Each worker makes her own independent judgment of the benefits of the new site. She returns and communicates her findings: the direction, distance, and level of optimism about the site. Other scouts then go to the site and make their own judgment. While they continue to recruit and visit, the enthusiasm for less hospitable sites gradually wanes, while more scouts commuincate the location of the better site.
Ultimately, all the scouts communicate through their movements about the chosen site. When about 15 or so scouts are outside the new home and about another 30 to 50 are inside, the decision is made, and the scouts start instigating the move.
Lessons?
- The process takes enough time to ensure a hasty decision is not made; on the other hand it does not go on for more than a few days.
- The bees stay together and come to a decision even if the new home is not perfect.
- The enthusiasm of the bees in the minority decays over time if others find the site inhospitable. No one is overruled, yet no one stubbornly remains attached to the less hospitable home. Each bee changes her “opinion” on her own.
- A late option or an option only visited by one bee can ultimately affect the whole colony if others are supportive after they visit.
- The move relies on many independent judgments, not following a leader. The queen bee is not involved in this decision at all.
From Science News, May 9, 2009