The Special Language of Bees

Study of bee language now has advanced to differentiation of bee dialects. Some years ago Dr. Karl von Frisch of the University of Munich established the fact that bees actually possessed a means by which they could communicate with each other and without which the remarkable organization within the swarm would have been nearly inexplicable. Their language consists primarily of signs, like that of deaf and dumb persons. Dr. von Frisch reached the point where he could get some idea of what the bees were talking about and even predict their behavior from their conversation.

Recently Dr. von Frisch has found that different varieties have quite different languages, perhaps as far apart as French and German; one variety cannot tell what another is discussing. He has gone one step further—to the discovery that the insects probably talk also in sounds that are inaudible to the human ear. The audible buzzing is not a means of communication.

“There are indications,” he says in a report to the Rockefeller Foundation, “that sounds, probably in the supersonic range, play a role in their communications.

“Physiologically it would be interesting to know how they judge distance. Their dances indicate with remarkable exactness the distance between the hive and the feeding place. How do they adjust themselves to the changing positions of the sun when they use it as a compass? Apparently they have an excellent memory for time, for they seem to know that the sun at a certain time will occupy a certain place in the heavens.”

Dr. von Frisch and his colleagues at the University of Munich are also making an intensive study of the insect eye and the physiology of the insect sense of smell. Previous research has shown that worker bees have a special scent gland under voluntary control. Only when a good source of nectar is found is the fragrance, evidently quite powerful and attractive to other bees, released. Then it permeates the immediate neighborhood. It is the bee language equivalent for the word “Here.” When a cruising worker gets a whiff of this odor it knows there is a plentiful supply of nectar close at hand and starts a search for it.

Bees cannot distinguish red from black, Dr. von Frisch has found. This probably is the reason so few red-blossoming plants depend on these insects for distributing their pollen. Nearly all red-blossoming species depend on birds and butterflies, both of which are acutely sensitive to red. One notable exception, however, is the European poppy whose brilliant red blossoms carpet the landscape in late Spring. The German experimenter has found that these blossoms are not “red” to the bee. They possess a color which cannot be described because it cannot be experienced by the human eye. The poppy blossoms reflect a great deal of the ultraviolet light in sunshine and to this the bee eye is extremely sensitive. The color must be quite different from any of the shades at the blue end of the spectrum which are visible to man. To the bee it is probably somewhat like violet.

Even the more or less degenerate human nose can be trained to discriminate some of the bee odors that apparently have so much meaning in the life of the hive. After practising for a few months Dr. N. E. McIndoo of the U. S. Department of Agriculture was able to recognize the three castes—queens, drones and workers—merely by smelling them. With more practice he was able to make even finer discriminations, as he reports:

“The younger the workers the less pronounced is the odor emitted. To the human nose the odor from nurse bees and wax generators is much less pronounced than is that from old workers. Workers just emerged from the cells have a faint, sweetish odor, but lack the characteristic bee odor and workers removed from the cells just before they begin cutting their way out omit a still fainter sweetish odor.

“Old queens have a strong sweetish odor, while that of queens just emerged from cells is much pronounced as is the bee odor of the workers. The majority of old drones have a faint odor while every young drone has a stronger one. It is slightly different from that of young workers and is less sweetish.

“All the offspring of the same queen seem to inherit a peculiar odor from her, which becomes the family odor. Apparently each worker emits an individual odor which is different from that of any other worker.

“Of all odors, that of the hive is most important. It seems to be the most fundamental factor upon which the social life of the colony depends, and upon which the social habit perhaps was acquired.”

Taste discrimination is roughly parallel to that of humans. The bee certainly can distinguish the primary tastes, sweet, salty, sour and bitter. It naturally is keenly sensitive to different degrees of sweetness, yet some sugars which are extremely sweet to man are tasteless to the insects. The same is true of such sweeteners as saccharin. The bee’s sense of smell also runs parallel to that of man, both in the ability to discriminate fine difference in odors and in the thresholds of sensitivity. This appears to be a very important factor in the location of nectar-bearing flowers. However, the bee appears unable to detect an odor from any great distance. It is probably due to the sense of smell that scout bees are able to locate good feeding grounds. After marking them with their own peculiar secreted odor they return immediately to the hive to tell the others about them. The dance of a returned scout varies in intensity according to the richness of the find and the workers who witness it become correspondingly excited. If the scout executes only a feeble dance there is only a small exodus from the hive.