CAUSE OF FEUD BETWEEN ANTS OF THE SAME SPECIES. 329 



with workers hatched in my artificial nests between August 8 

 and 28, 1902, from C colony pupae. This nest I here refer to 

 as Section B. 



The ants in the two sections were fed with the same kinds of 

 food on the same days and had in all respects similar envi- 

 ronment. 



On July 12, 1903, an ant-worker hatched from a pupa that 

 had been previously removed from Section B, and isolated in a 

 Petri cell. This worker was kept in isolation until she was six 

 days old. I then introduced into her cell a worker, the off- 

 spring of a queen in section A, and she attacked this worker 

 with great violence, although the worker was of an age precisely 

 her own and had likewise been isolated from the pupa-stage. 

 The only difference between the two lay in the age of their re- 

 spective mothers, one queen mother being two years old and the 

 other one year old. Neither of these callows had, previous to 

 their meeting, ever smelled any other ant, and had they had the 

 same odor they would have affiliated, as do similarly reared ants 

 that are the progeny of the same queen or of sister queens. 



On August 24, 1903, when the ant from Section A, used in 

 the foregoing experiment, was forty-three days old and was 

 occupied in the care of introduced larvae, I put into her Petri- 

 cell, where she had always lived alone, a callow five days old, 

 reared in isolation from a pupa taken from Section B. The resi- 

 dent ant at once attacked and dragged the callow. In this case 

 the offspring of the older queen attacked the offspring of the 

 younger queen, though that offspring was much younger than 

 herself. 



Other experiments coincided in their results with the two here 

 recorded. 



A cause of feud between ants of the same species living in 

 different communities is a difference of odor arising out of differ- 

 ence of age in the queens whose progeny constitutes the commu- 

 nities, and difference of age in the ants composing the com- 

 munity. 



MARINE BIOLOGICAL LABORATORY, WOODS HOLE, MASS., 

 September, 1903. 



