A review of the forms and functions of the eight mechanical (non-chemical) signals that worker honey bees produce and that human beings have deciphered.

Imagine that you are a worker bee…

As you begin to read this article, I ask you to imagine that you are a worker bee, and that you have been toiling as a forager but are now resting, perhaps even sleeping, inside your colony’s hive. Suddenly, a peppy nestmate comes along, grabs hold of you with her forelegs, and rapidly shakes her body up and down for a few seconds. You have just received the shaking signal (Diagram 1). Its message is “Hey you. Time to get cracking!” Usually, this signal is produced by active foragers to rouse inactive foragers, but sometimes it is directed at a colony’s queen, to prepare her for departure in a swarm.

Now that you have been shaken, you groom your body to remove the bits of wax that fell onto you while you were resting. To do so, you swipe your antennae using the antenna-cleaner structures on your forelegs, and you brush the wings and undersurfaces of your body using the hairs and combs on your legs. But if you feel a need for cleaning around the bases of your wings (and other places you cannot reach), then you spread your legs widely, grip the comb firmly with all six pairs of tarsal claws, and (for a few seconds) rock your body side to side at a frequency of about four rocks per second. You are performing the grooming invitation dance (Diagram 2). Almost always, and within just a few seconds, a hive mate will turn to you and start cleaning – by nibbling – the hard-to-reach places on your body.

A minute or so later, you are ready to resume work as a forager. Now you walk to the dance-floor region in your colony’s nest – the areas of comb just inside its entrance – and then you either depart for the flower patch you visited the day before or linger to follow a waggle dance (Diagram 3). Doing the latter might stimulate you to resume work at your former flower patch or it might steer you to work at a new one.

Now, imagine that you have worked at a patch of flowers laden with rich nectar and are coming home highly excited by your foraging success. If you scurry inside the hive and are met in less than 15 seconds by a hive mate functioning as a nectar receiver, then you will advertise this flower patch by performing a waggle dance. But if you scurry inside and must search 60 seconds or more to find a hive mate that is willing to receive your nectar, then you will perform a tremble dance (Diagram 4). You will produce this signal because the rather long unloading delay that you just experienced has informed you that your colony needs to activate more of its middle-aged members to function as nectar receivers. Your tremble dance is a ‘call’ for bees to fill this need. To fully exploit the honey flow, your colony needs many workers to perform the tasks of receiving, processing and storing the flood of fresh nectar that its foragers are bringing home.

And now, imagine you are a nest-site scout

At this point, dear reader, I need you to switch to imagining that you are a worker bee that is functioning as a nest-site scout. The first two signals that you will produce in this role are worker piping (Diagram 5) and buzz running (Diagram 6). At first, you produce these signals inside your home. You produce piping signals to tell your nestmates to warm their flight muscles in preparation for their mass exodus in a swarm. Then, when you sense that your nest mates have their flight muscles sufficiently warmed up, you produce buzz runs to trigger the explosive departure of some 10,000 bees, including your queen, from your home. From start to finish, the exodus of your colony’s swarm takes only a minute or two.

After the swarm bees have settled into a cluster on a nearby object (such as a tree branch or a stop sign), you and your fellow nest-site scouts use two signals to conduct the collective decision-making process to choose which one of several potential home sites is best for your group’s future home. One of these signals is well known to your beekeeper: the waggle dance. 


S/he knows that you use this signal to advertise profitable food sources and desirable home sites. The other signal is the stop signal (Diagram 7). It is not so well known. This is because the biologists who study your behaviour discovered this signal only recently. This is a very brief (c150 milliseconds) vibrational signal with a frequency of about 350 cycles per second, and is delivered by you momentarily butting your head against a waggle dancer. You use this signal to inhibit waggle dancing to advertise potential nest sites other than the one that you favour. The stop signal creates cross-inhibition between the groups of nest-site scouts advertising different possible home sites, and this helps you and your fellow nest-site scouts avoid the problem of coming to a split decision over two equally good sites.

Once you and the other nest-site scouts have reached a decision, you again use your worker piping and buzz-run signals to stimulate the swarm to warm up and launch into flight to move to its new home site. When every bee is airborne, you produce signals of another sort to steer the movement of the airborne swarm: streaker flights (Diagram 8). These are the high-speed (c35km/hr) flights that you and your fellow scouts make through the top of the swarm cloud. They point in the direction of the new dwelling place. It remains a mystery, however, how you scout bees apply the brakes to your swarm’s cloud of swirling bees as it approaches its destination so that it stops right at your new home site. Indeed, there is much about your communication skills that begs further investigation by inquisitive humans.