SCENT LANGUAGE OF HONEY BEES — RIBBANDS 375 



allowed to enter the strange colony, but when nectar was short the 

 strangers were attacked and thrown out, often being killed in the 

 process. 



In further experiments, carried out at the end of the season when 

 no nectar could be collected, bees from one of the two colonies were 

 trained to visit dishes filled with sugar solution, but no syrup was 

 made available to bees from the other colony. When this happened 

 I found that the colony whose foragers were collecting syrup would 

 tolerate strangers from the other colony, although these intruders 

 went into it without food; on the other hand, the colony that was 

 not foraging attacked strangers even if they were carrying full loads 

 of rich sugar solution. This experiment showed that the chance of 



Figure 2. — Community defense. Two hives are placed togetiier, with their very small 

 entrances only 2 inches apart. Empty boxes in front of the hives receive any dead 

 or injured bees. 



successful entry was determined by the behavior of the bees in the 

 colony which the intruder tried to enter. The fact that robbing 

 occurs when foragers are not otherwise employed and that colonies 

 are mostly guarded by unemployed foragers makes this result imder- 

 standable. 



The production of a common and distinctive odor, which enables 

 the colony to defend itself against members of other honey-bee com- 

 munities, is a very important consequence of the habit of food sharing, 

 and it must have provided an important stimulus for the evolution 

 of this habit — better sharing means better defense, and so a greater 

 likelihood that the community will be able to survive and to perpetuate 

 its kind. 



370930—56 25 



