This hive is occupied by about 60,000 honeybees. In the course of a year, they collect more than 20 kilograms of honey if the nectar flow is good.

The honey is stored in the combs of the upper floor, which is being removed here. This hive is not suitable for investigating bee dances, because it's impossible to look into the dark spaces between the combs in order to observe the bees dancing on the vertical comb surfaces.

One would also have to protect one's face and hands from the many aggressive bees. For the purposes of the following experiments, a small swarm is isolated in a so-called observation hive.

Without a protective covering, one can view the bees at work through the pane of glass. As for these investigations, a particularly gentle strain of bees was bred. They could even be observed after careful removal of the window.

The hive has only two combs, arranged one above the other. Just outside the entrance to the hive, a feeding place with sugar syrup is set up and then moved several paces away from it, together with the sucking bees. They are hardly disturbed by this, and later return to the new feeding place.

The foraging bees are so absorbed in feeding that they can easily be marked with a fine hairbrush. These bees with the white marking are subsequently identifiable in the hive as foragers coming from a near distance.

Back at the hive, each forager gives up the collected food to other hive mates. Then she begins to dance a round dance, which takes her in circles, alternately clockwise and anticlockwise. This round dance informs the follower bees

that a source of food is available in the close vicinity. It urges the recruits to swarm out and forage near the hive. During the round dance, the forager describes circles alternately to the left and right. The experimenter removes the feeding table

in easy stages ever further from the hive. He is now approaching the 100 metre mark, accompanied by several bees which have followed him. These bees are now marked with a blue spot.

Returning home from a feeding place 100 metres away, the bees clearly show the transition from the round dance to a waggle dance.

The dancer wags her body vigorously from side to side, making about 15 swings per second. This directional waggle run is performed between two loops. Two essential pieces of information imparted by the waggle dance concern the direction to and distance from the food source.

First, the indication of distance. Both the duration of each waggle run as well as the number of waggle runs per unit of time indicate the distance from the food source. What follows is an investigation of the indication of distance in four stages.

To this end, the number of runs in the arbitrarily selected time unit of 15 seconds is counted as follows. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

So, a feeding place at a distance of 100 metres is indicated by 10 wagging runs per quarter minute. Now a distance of 200 metres has been reached over stubble fields and beetle ottemans.

The foragers at this distance from the hive are given yellow group markings. The waggle dance now becomes more prominent. It takes longer and the directional waggle runs follow one another at wider intervals.

Again, the number of runs for each quarter minute is counted. 1, 2, 3, 4, 5, 6, 7, 8.

So, we now have only eight runs every 15 seconds, two less waggle runs than at 100 metres distance.

In the course of the experiment, the 500 metre mark has now been reached. The bees are marked with red spots. The dance rhythm is even slower and the waggle run takes correspondingly longer.

1, 2, 3, 4, 5, 6. At 500 metres, therefore, only six runs are counted.

After three days, the 1000 metre mark is reached in this vineyard. The foragers are here marked with a green dot.

The dance rhythm is still slower and each run is noticeably longer. 1, 2, 3, 4, 5.

At 1000 metres, there are only five waggle dances to a quarter minute. So, four norm values have been calculated for distance indication. The number of waggle runs per 15 second unit are plotted on the graph against the distance.

Ten waggle runs at 100 metres, eight at 200 metres, six at 500 metres, five waggle runs at 1000 metres distance from the source of food. An asymptotic curve is traced.

Follow-up experiments confirm the further tendency of the curve. At 10,000 metres, the bees no longer find it worthwhile to alarm their hive mates. The dances are discontinued. The outer limits of the foraging area of a bee are at 12,000 metres.

The most important part of the dance is the waggle run. Its signal effect is accented acoustically in the form of short sound pulses giving a rasping note. Rhythmical contractions of the flight muscles generate sound frequencies of approximately 280 hertz

which are emitted via the wing surfaces. Only these acoustically accompanied dances are able to alarm the recruits. The duration of the sound pulses also provides the most accurate measure of the distance to the food source. Besides the sound pulses, this synchronous sound and picture recording

also exhibits the begging calls of the follower bees. Through these, the forager bees are induced to regurgitate samples of food. In the following sequence, the occurrence of these short, sharp begging calls will be proclaimed one second in advance by the presence of a white dot at the lower edge of the frame.

Indicating distance by means of the waggle dance depends on the forager's ability to estimate accurately on the outward flight to the feeding place just how far this is from the hive. By attaching 33 milligram brass weights

to several field bees under CO2 anaesthesia, their body weight was increased. This experiment serves to prove that the honeybee's estimation of distance is the energy expended during the flight. The artificially burdened foragers would indicate a greater distance in their dance than actually exists between feeding place and hive.

First of all, here's a green-marked, unweighted forager who has returned from the feeding table 1,000 metres away. She takes 15 seconds to make five runs. Now a bee with brass weights begins to dance.

She has returned from the same 1,000 metre distance feeding place as the green-marked one but takes three seconds longer for her five runs and thus shows 300 metres more than she has actually flown. 18 seconds correspond to a distance of 1,300 metres.

Here is a weighted and an unweighted bee. The weighted forager lags behind the unweighted one in the rhythm of her dance. In correlation with their increased energy consumption, bees also exhibit a slower dance tempo when they've encountered a headwind or flown uphill

on the outward flight to a food source. Now to direction indication. The waggle dance can only effectively indicate the exact location of a source of food if it denotes the direction as well as the distance. For direction indication, the sun provides a point of reference. In order to understand more fully what happens on the vertical comb surface

in the darkness of the hive, it's important to consider the original dance on the horizontal plane. It can be observed on the alighting board on hot summer days. The wagging run points directly towards the destination. The bee dancer orientates herself at the same angle to the sun as during the preceding outward bound flight to the food source.

The alignment of the waggle dance to the sun's position can be impressively demonstrated by rotating a horizontal comb. To the left, the process of rotation.

To the right, the simultaneous close-up of the waggle dance. Dancing bees find no difficulty in compensating for the rotation of the comb surface and on no account turn with the substrate. Unwaveringly, they maintain the angle between the direction to the food source and the sun's position,

which they have established menotactically on the outward foray. This angle is also maintained during the waggle dance on the vertically orientated comb in the hive. This is especially noticeable when a comb is rotated from the horizontal to the vertical.

The bee dances at an angle of 110 degrees to the sun on the horizontal. This direction points to the food source. When the comb is in an oblique position, the direction of the waggle run has already changed. Now the dancer no longer orientates to the position of the sun but to another system of reference,

the earth's field of gravity. This gives the perpendicular axis, so the bee transposes the angle subtended by the sun's position and the food source to the perpendicular axis in the gravity field. This correlation is now illustrated diagrammatically.

At 8.30 in the morning, a foraging bee flies towards a source of food due south of the hive. The sun's position is east-south-east. The flight path of the bee runs some 80 degrees to the right of the sun.

On her return to the hive, the wagging run of her dance on the vertical comb accordingly measures 80 degrees to the right of the perpendicular. So the bee transmits the information that the feeding place is 80 degrees to the right of the sun. In the course of the day, the sun's relative position changes.

The angle between it and the food source narrows. During the waggle dance, the angle between the perpendicular and the waggle run direction on the vertical comb diminishes correspondingly. When the noonday sun is due south of the experimental feeding place,

the bee dances straight upwards on the plumb line. She thus informs the recruits that the food source is in the direction of the sun, that is, due south. In the afternoon, the angle between sun position and food source increases in the opposite direction.

Correspondingly, the direction of the bee's straight run moves anticlockwise. Round about 16.30 hours, the forager dances some 80 degrees to the left of the perpendicular, which corresponds with a flight route to the food source 80 degrees to the left of the sun.

Now, the dancer shows that the feeding place is to the left of the sun. During the course of the day, with constant source of food, the straight waggle run on the vertical comb alters with the same angular velocity as the sun's relative position alters.

So, the bee transposes the angle between flight path and sun position to the Earth's field of gravity. To demonstrate that the recruits have understood and act upon the information imparted by the dance, several of them have been marked with white dots.

The time is 10 a.m. The observer at the 1,000-meter feeding place records whether white-marked recruits arrive there.

10.40. Forty minutes later, the first follower bees show up. Without further help, they have found the source of food from the information imparted by the dancing bees. Pollen gatherers, who bring home the grains stuck together with nectar

attached to their pollen baskets, also announce the position of a source by means of waggle dancing. These slow-motion shots illustrate each phase of the waggle dance in detail. The powerful sideways sweeps of the whole body during the straight run and even the whirring of the wings associated with the acoustic signals

are clearly visible. The recruits endeavour to keep up with the turns taken by the dancer and maintain close contact with her by the antennae. Only in this way can they receive the full information

about distance and direction. In addition, they learn from the perfume adhering to the dancer's hairs which type of flower she has visited. The waggle dance also provides information about the quality and abundance of the food source. This information is imparted by the acoustic signal of the waggle run,

the sound pulses and the duration of the bees dance which may last anything from a few seconds to three minutes. In its precision and the wide variety of information conveyed, the dance of the honeybee represents a unique form of communication in the animal kingdom

as it makes use of symbolic signals and the communication takes place at spatial removal from the source of food indicated, the dance of the honeybee must even be conceded to exhibit some of the basic elements of a genuine language.