274 ENTOMOLOGY 



ever-fascinating subject of study to the naturalist, and well repay the 

 most critical observation. While each species has its characteristic 

 habits, ants in general have many customs in common. 



Thus ants of one colony exhibit, as a rule, a pronounced hostility 

 toward ants of any other colony, even one of the same species, but recog- 

 nize and spare members of their own colony, even after many months 

 of separation and though the colony may number half a million indi- 

 viduals. This recognition is effected by means of an odor, distinctive 

 of the colony and apparently inheritable. When an ant is washed and 

 then restored to its fellows, it is treated at first as an intruder and may 

 even be killed. The same is true when the ant has been smeared with 

 juices from the bodies of alien ants. According to Miss Fielde, workers 

 of colony A, smeared with the juices from crushed ants of colony B and 

 then placed in colony B are received amicably, but at once set about 

 to destroy their hosts, like "wolves in sheep's clothing." These state- 

 ments apply only to workers, however, for alien larvae and pupae are 

 frequently captured and reared by ants, and Miss Fielde states that 

 kings of one colony of Stenamma when introduced into another colony 

 are even cordially received. 



Some of the most careful students of the habits of ants agree that 

 these insects can communicate with one another. An ant discovers a 

 supply of food, returns toward the nest, meets a fellow worker, the two 

 stroke antennae and then both start back to the food; before long other 

 members of the colony swarm to the prize. It has been thought that 

 the odor of the food or some other odor, left by the first ant, serves as a 

 trail for the other ants to follow. Bethe, indeed, infers from his experi- 

 ments that this phenomenon is purely mechanical and involves no 

 psychical qualities on the part of the ants. His own experiments, how- 

 ever, show that one ant can inform another by means of an odor as to 

 the whereabouts of food which is certainly one form of communication. 



Ants avoid sunlight as a rule but prefer rays of lower refrangibility 

 to those of higher. Upon exposing ants to the colors of the spectrum, 

 as transmitted through glasses of different colors, Lubbock found that 

 they congregated in greatest numbers under the red glass and that the 

 numbers diminished regularly from the red to the violet end of the spec- 

 trum, there being very few individuals under the violet glass. 



Miss Fielde, experimenting with queens, workers and young of Ste- 

 namma fulvum piceum in an artificial nest, covered half the nest with 

 orange glass and half with violet. "The ants removed hastily from 

 under the violet as often as an interchange of the panes was made, once 



