THE SENSES OF INSECTS McINDOO. 467 



odor is very pleasant and is as characteristic for queens as is the bee 

 odor for "workers. 



The majority of old drones have a faint odor, while almost every 

 young drone has a stronger odor. This odor is slightly different from 

 that of young workers and is less sweetish. 



By means of specially devised experiments the "writer proved that 

 the bees themselves can distinguish a much greater variety of smells, 

 and that these play a most important part in their lives. 



It is certain that a queen gives off an odor, and it seems reasonable 

 that the odors from any two queens would be slightly different. All 

 the offspring of the same queen seem to inherit a particular odor from 

 her. This odor, called the family odor, perhaps plays little or no 

 part in the lives of bees, for it is certainly masked by the other odors. 

 Drones seem to emit an odor peculiar to their sex, but little can be 

 said about it. It seems certain that each worker emits an individual 

 odor which is different from that of any other worker. It is also 

 probable that the wax generators and nurse bees emit odors slightly 

 different from those of the field bees. 



Of all the odors produced by bees, the hive odor is probably the 

 most important. It seems to be the fundamental factor or principle 

 upon which the social life of a colony of bees depends and perhaps 

 upon which the social habit was acquired ; without it a colony of bees 

 could not exist. The hive odor is composed chiefly of the individual 

 odors from all the workers in a hive and is supplemented by the odors 

 from the queen, drones, combs, frames, and walls of the hive, etc. 

 From this definition it is easily understood why no two colonies have 

 the same hive odor. The hive odor of a queenless colony is perhaps 

 considerably different from that of a colony which has a queen. The 

 absence of a queen odor in the hive odor probably explains why the 

 workers in a queenless colony are irritable and never work normally. 

 All the bees — workers, queen, and drones — in a colony carry the hive 

 odor of that colony on their bodies among the hairs. This odor serves 

 as a sign or mark by which all the occupants of a hive know one an- 

 other. Since the queen and drones are " aristocrats," they seem to 

 disregard the sign that has been thrust upon them, but whenever a 

 queen enters the wrong hive she soon "realizes" that she wears the 

 wrong badge. 



Worker bees returning to the hives from the field pass the guards 

 unmolested because they carry the proper sign, although the hive 

 odor that they carry is fainter than when they left the hive, and it 

 is also partially masked by the odors from the nectar and pollen 

 carried by these bees. 



Bees kept in the open air for three days lose all the hive odor 

 carried on their bodies, but each bee still emits its individual odor. 

 When a colony is divided the hive odoi in each half soon changes, 



