374 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 5 



discoveries of Prof. Karl von Friscli have explained why this does not 

 happen. He proved that successful foragers, returning to their hive, 

 give samples of their booty to their hive mates so that they may know 

 what scented food they should search for, and immediately afterward 

 the foragers perform a dance which tells their hive mates the direction 

 and distance away from the hive to the crop. 



Von Frisch's students have shown that this message system is so 

 widespread that bees seldom need to find new crops for themselves ; 

 nearly all of them collect from crops that they have been told about. 

 In consequence, the colony, not the individual bee, becomes the forag- 

 ing unit, and neighboring colonies usually gather quite different pro- 

 portions of the various kinds of nectar and pollen that are available 

 to them. 



Thus, by food sharing between forager and recruit different colonies 

 collect different food supplies, and by food sharing between all the 

 bees of each colony those supplies are so evenly distributed that the 

 bees of each colony produce the distinctive odor that enables them 

 to recognize one another. 



THE USE OF THE DISTINCTIVE ODORS 



In nature one does not expect complex mechanisms to be preserved 

 unless they are of some advantage to the animals that possess them, 

 so it is legitimate to ask what use the honey-bee community makes 

 of its distinctive odor. What advantage, if any, does the honey bee 

 gain from its ability to recognize companions? If one bee meets 

 another bee on a flower, it is doubtful whether either would obtain 

 any advantage from being able to recognize the other as a hive mate ; 

 it seems highly improbable that the distinctive odors have evolved 

 and been perpetuated because they were of use in this situation. 



But there is one circumstance in which the recognition of hive mates 

 is of great value to bees. At those times of the year when there are 

 insufficient flowers to provide all the bees with food, they often try 

 to steal the honey that is stored away in the honeycombs of other 

 colonies. In such conditions the ability to recognize hive mates and 

 to distinguish them from all other honey bees will enable the colony 

 to defend itself against attempts at robbery by members of other 

 colonies. 



However, the honey-bee community does not defend itself by attack- 

 ing every invader that does not possess the community odor. 

 Strangers are only attacked in certain circumstances. In order to 

 investigate those circumstances, two colonies of differently colored 

 bees were placed close together, with their entrances only 2 inches 

 apart, so that bees often went into the wrong colony by mistake (fig. 

 2). When good supplies of nectar were available, the intruders were 



