Most people have heard of the waggle dance, the one where a forager tells the hive where the flowers are. Fewer people know there is a second dance, and it says close to the opposite thing. Karl von Frisch first wrote it down in 1923 and called it the Zittertanz, the trembling dance. He could not work out what it was for, and neither could anyone else for about seventy years.
It does not look like communication at first. A forager walks in and starts to shake. Thomas Seeley described it as three motions happening at once: she jiggles her body side to side, she swings her head to a new heading every second or so, and she walks slowly across the comb the whole time. She can keep that up for half an hour, wandering through the brood nest while everyone else works around her.
Seeley worked out the trigger in 1992. A forager who finds a rich patch of flowers does not store her own nectar. She has to hand it off to a receiver bee waiting inside, and if she has to search a long time to find one, she trembles instead of waggling. So the message is not really about the flowers. It is that more nectar is coming in the door than the hive can currently handle.
Good news you cannot handle yet is still a problem, and the bees have a dance for saying so.
The dance does not just complain, it fixes things. Seeley, Kühnholz and Weidenmüller showed in 1996 that tremble dancing pulls more bees off other jobs and puts them on nectar receiving. At the same time it quiets the waggle dancing going on nearby, so fewer foragers head back out for more. The colony clears its own bottleneck, and no bee anywhere is in charge of deciding that.
We think about that one more than you would guess. A busy day is only a good day if the people up front can actually take care of you, so when it gets loud in here we move people toward the line instead of chasing more of it. It is the same reason we have never sold a car over MSRP. Being worth walking into is the whole job, and Libertyville has a long memory.
