Why do bees dance?

How the code works

• Direction: the angle of the waggle run away from vertical equals the angle of the food source away from the sun. Straight up means fly towards the sun; sixty degrees left of vertical means sixty degrees left of the sun.
• Distance: the duration of the waggling portion encodes it — roughly one second per kilometre, though the calibration varies between subspecies.
• Quality: a better food source produces a more vigorous, longer-repeated dance that recruits more followers.
• Time correction: the sun moves, and a bee dancing in a dark hive adjusts the angle to account for how far it has travelled since she flew. She is compensating for the passage of time without seeing the sky.

How it was worked out

Karl von Frisch decoded it over decades of work and shared the 1973 Nobel Prize in Physiology or Medicine for it. The claim was contested for years — it seemed extravagant for an insect — and was settled decisively by experiments including a robotic bee that could perform dances to order and recruit real foragers to locations the experimenters chose.

The other dances

• The round dance, performed for food very close to the hive, which conveys 'nearby' without a specific direction.
• The tremble dance, which signals that foragers are returning faster than house bees can unload them and recruits more receivers.
• Nest-site dances, performed by scouts on the surface of a swarm cluster, advertising cavities they have found. The swarm reaches a genuine collective decision this way, and it is one of the best-studied examples of distributed decision-making in any animal.