A honeybee comes home from a good patch of flowers. The hive is pitch black, the comb hangs vertically, and the flowers may be more than a kilometre away. Within minutes, other bees fly out and find the same patch. She told them where it is. She did it by walking in a figure of eight and shaking her abdomen.
The move is called the waggle dance, and it is one of very few cases in which an animal describes a place that is somewhere else. It carries two numbers: a direction and a distance. Try it before reading on.
The dance has a straight stretch in the middle, the waggle run, where the bee shuffles forward while shaking her body from side to side roughly thirteen to fifteen times a second. Then she circles back to the start, alternating left and right, and does it again. The loops are only the walk back. The message is in the straight part.
Outside, a forager steers by the sun. Inside there is no sun, so the dance swaps it for the one direction every bee in the dark can feel: gravity. Straight up the comb stands for "toward the sun". A waggle run pointing straight up says "fly toward the sun". Straight down says "fly directly away from it". A run tilted 40° to the right of vertical says "fly 40° to the right of the sun". Drag the sun around the map and watch the dance tilt, even though the flowers have not moved.
The second number is time. The farther the food, the longer each waggle run lasts. In a 2021 study that trained Carniolan honeybees to feeders at known distances, waggle runs averaged about 0.41 seconds for 100 metres and 2.20 seconds for 1.7 kilometres. That is close to one extra second for each extra kilometre. The same study found the line bends a little, flattening at longer distances, and other subspecies use noticeably different rates. A dance is a local dialect.
For food very close to the hive the waggle run shrinks to almost nothing and the bee simply turns in circles, a "round dance" that says little more than "nearby, go and look".
How does a bee know how far she flew? Not by counting wingbeats or burned energy. Her odometer is visual: she measures how much scenery streamed past her eyes. Researchers showed this by sending bees through narrow tunnels lined with busy patterns. Because the walls were so close, the image rushed by, and the bees came home and danced for a distance many times longer than the tunnel really was.
A sun-based code has an obvious problem: the sun drifts across the sky all day. Bees correct for it. A forager who keeps dancing for a long time inside the dark hive gradually shifts the angle of her waggle runs to match where the sun has moved to, without going out to check. She carries an internal clock and a learned picture of the sun's daily path.
People had noticed for a very long time that bees recruit each other. Aristotle wrote that a returning bee is followed by three or four companions. The code itself was worked out by the Austrian zoologist Karl von Frisch, who moved dishes of sugar water around the countryside and timed dances with a stopwatch. He shared the 1973 Nobel Prize in Physiology or Medicine with Konrad Lorenz and Nikolaas Tinbergen.
Sceptics argued for decades that recruits might just be following the smell of flowers on the dancer. In 2005 a team fitted recruits with tiny radar transponders and tracked their flights. The bees left the hive and flew straight in the direction and for the distance the dance had indicated. Recruits that were carried to a different release point before take-off still flew that same compass course, ending up where the food would have been if they had started from the hive. They were flying the instructions, not a scent trail. Smell helps at the end, to pin down the exact flowers.
The dance is noisy. Successive waggle runs for the same patch scatter by several degrees, and a follower usually tracks a number of runs before leaving, in effect averaging them. Many do not find the food on the first try. Experienced foragers often ignore dances altogether and go back to patches they already know.
Try the quiz above. You will probably land within a few hundred metres, with one look at one bee. A follower in the hive does it by touch and vibration, in total darkness, in a crowd.