Honey bees listen to the dance.

Honey bees listen to the dance

Honey bees dance to tell each other precisely where food lies. Scientists have largely decoded bee dances, but they do not yet understand exactly how one bee perceives another's dance signals. Now, for the first time, researchers have shown directly that honey bees can detect and discriminate among airborne sounds simulating those created in their dances, says study coauthor William F. Towne of Kutztown (Pa.) University.

Scientists have suspected that sounds play an important role in the bees' dance communication, which takes place in the dark. Until now, however, no one could confirm that bees "hear" airborne noises. Towne and German colleague Wolfgang H. Kirchner gave feeding honey bees an electric shock shortly after exposing them to a sound of either 265 hertz, the frequency of a dancing bee's wing vibrations, or 14 hertz, the frequency of a dancer's abdominal waggling. The bees learned to withdraw from the feeder in response to the sound alone.

The experiment's success stemmed from the kind of sound the scientists produced. They used a loudspeaker to force a glass tube to resonate in a way that caused an unusual amount of air-particle movement, one component of sound. Human hearing relies on the other sound component, oscillating pressure waves. But by allowing bees to enter a closed tube in which the two components were spatially separated, the scientists showed that the insects respond only at places of air-particle movement, says Towne.

The bees probably detect shifting air particles with organs lying at the hinge of each antenna, say the researchers. These "respond best to air movement of 250 to 280 hertz, the frequency of the dance sounds," they note in the May 12 SCIENCE.

According to Princeton (N.J.) University biologist James L. Gould, the new work has prompted researchers at Odense University in Denmark to create a dancing-bee robot that can recruit real honey bees to food-gathering spots.