14 ADELE M. FIELDE. 



V. EFFECTS OF THE PROGRESSIVE ODOR IN THE COMMUNAL 



LIFE OF ANTS. 



Since the queen is ordinarily the earliest occupant of the ant- 

 nest, and since her callow young have the same odor as herself, 

 the odor of her earliest nest must at first be the same as is that 

 of the queen. Probably this odor is at all times dominant in the 

 permanent nest ; but as the progressive odor of the workers is 

 gradually added thereto, the nest-aura would be thereby modi- 

 fied. The change in the nest-aura, cumulative with the age of 

 the colony and the increase of the inmates, would be so gradual 

 that all habitants of the nest would at all times find it familiar 

 and therefore congenial. The greater dominance of the queen's 

 odor in the earlier nest may be the cause of the persistence with 

 which many workers cling or return to the old habitation even 

 after the majority of the colony has for sound reason removed to 

 a new abode. 



It appears probable also that diffused ant-odor is in direct ratio 

 to bulk of ant-body, and that a cause of the common activity of 

 workers in adding the lesser to the larger pile of brood, some- 

 times even against the inhibitory effects of light, is due to the 

 more manifest odor of the larger pile. 



I have at different times during several years observed in my 

 artificial nests a most curious phenomenon among ants that had 

 long lived amicably together. Several or many workers were 

 seen standing around one ant as if holding a court of inquiry con- 

 cerning this associate. Sometimes the associate is proscribed, 

 sometimes rent limb from limb. This extraordinary behavior is 

 probably due to the victim having attained a progressive odor that 

 is obnoxious to many other inmates of the nest because unknown 

 to them. This might happen to an aged ant whose horde of com- 

 panions were all young. It might also happen that in prowling 

 for food, or in raids made on the nests of aliens, the worker ants 

 would bring in alien young for food, and that this much licked 

 and tended young would incur the progressive odor of the nurses. 

 At a later period the introduced ant might produce a progres- 

 sive odor unlike that of the multitude inhabiting the nest, and it 

 would therefore be doomed to destruction. Ostracisms or violent 



