NO. 2 RECOGNITION AMONG INSECTS McINDOO 35 



SO that by the end of the third day the original colony possesses a 

 hive odor so different from that of the other half of the colony, that 

 when the workers are removed from the two new colonies and are 

 placed together in observation cases, they fight one another as though 

 they had been separated all their lives. 



While a foreign hive odor calls forth the fighting spirit in workers, 

 the queen odor always seems pleasant to workers regardless of 

 whether the queen belongs to their hive or to another hive. Even 

 though the queen odor forms a part of the hive odor, it is probable 

 that this odor to the workers stands out quite prominently from the 

 hive odor. That workers do not miss their queen for some time after 

 she has left the hive, indicates that her odor thoroughly permeates 

 the hive odor and that whenever this odor grows faint the workers 

 " know " that she is not among them. 



There has been much speculation concerning the ruling spirit 

 or power in a colony of bees. The present writer is inclined to 

 believe that a normal hive, odor serves such a purpose. The hive 

 odor is a means of preserving the social Hf e of the bees from without, 

 and the queen odor which is a part of it insures continuation of 

 the social life within. As already stated the workers " know " 

 their hive-mates by the hive odor they carry. This odor insures 

 harmony and a united defense when an enemy attacks the colony. 

 The queen odor constantly informs the workers that their queen is 

 present. Even though she does not rule, her presence means every- 

 thing to the bees in perpetuating the colony. Thus by obeying the 

 stimuli of the hive odor and queen odor, and being guided by instinct^ 

 a colony of bees perhaps could not want a better ruler. 



All insects apparently emit odors, but only those of honey-bees 

 and ants have been carefully studied ; while the family odor among 

 ants seems to play an important role, it is probably of little or no use 

 among bees, because the hive odor has assumed such an important 

 part in recognizing the members of the same or of a different colony. 

 The progressive odor among ants is perhaps more highly developed 

 than it is among bees, because the duties of ants are more varied 

 than are those of bees and since slavery among ants is common. 



SCENT-PRODUCING ORGANS OF INSECTS 



In the preceding pages it is shown that insects, particularly ants 



and bees, recognize one another chiefly by means of odors, and since 



this is true they must have some means of producing these odors, 



because a hard substance like chitin is practically odorless to us and 



