Trained bees are numbered. When unnumbered bees join them at the feeder the scientists know the bees have "talked."

During daylight hours of every day of the year, bees forage among the thousand species of flowers in the forests of Panama, making hundreds of trips back and forth to the hive each day. But how do they know where to go?

In "Bee Lines" researchers David Roubik and James Nieh reveal how bees give each other directions in three dimensions - how far, how high and in what direction. First Roubik and Nieh mark a few bees with numbered tags - Alan tags #78- and train them to seek out a sugar-water feeder. Then, the researchers place the feeder at the top of a 120-foot tower. Can the numbered, trained bees communicate the tower's height to their untrained hive-mates?

At first, only trained bees show up at the feeder. But then, untrained bees join their mates, indicating that the trained bees have successfully communicated the feeder's height to their buddies. Similar experiments show the trained bees can also communicate distance and geographical direction. But how?

Roubik and Nieh remove all the trained bees from the hive. The untrained bees still find the feeder, so they are not simply following their more educated friends to the food source. Then the researchers place the feeder across a lagoon. The untrained bees still find it, so they are not using a scent trail to find their way either.

Neih helps Alan translate the "bee book.".

Not until James Nieh began videotaping hive activity did it become clear how the bees were communicating. When bees return to the hive with food, they make a series of buzzing noises, then do a brief dance accompanied by another series of buzzes. By comparing the bees that came in from different feeders, Nieh was able to decipher the bees' buzzing code. Short buzzes during the first series indicate the food came from near the ground, and the longer the pulse, the higher the food source. For sound made during the dance, the longer buzzes indicate farther sources of food.

It's still a mystery how bees communicate geographical direction, but, as Alan notes, maybe #78 will show them how it's done.

For more on this topic, see the web feature:
FRONTIERS Profile: Damian Elias