ANT COMMUNITIES 



along a depression made by a shallow surface drain to a 

 second nest under a gate that led through a party- wall 

 into a house yard. 



Apparently, the ants from the curb colony had fallen 

 upon the unctuous treasure which had dropped by their 

 door, but had been disturbed in their " feast of fat things" 

 by stragglers from the gate nest. These were attacked; 

 others came, and were also attacked. Messengers ran 

 to the gate nest for reinforcements; fresh squadrons 

 issued from the curb colony, and so the battle grew. 

 [McC. 11, p. 158.] It is probable that many like con- 

 flicts arise from rivalries for the possession of food ; and, 

 as in the above case, it is almost sure that a communal 

 war springs out of a quarrel between a few', who, appeal- 

 ing to civic partisanship, finally enlist in their contention 

 the two communities represented. Of course, conflicts 

 between separate genera and species are readily ex- 

 plained by race antipathy. 



Perhaps the most usual cause for the wars waged be- 

 tween our city Tetramoriums is the irritation produced 

 by the encroachment of the mining workers upon their 

 neighbors in the enlargement of their living-quarters. 

 This is the more likely, as the most common period for 

 the battles is the early spring, when the demand for 

 larger room is greatest for the accommodation of the 

 rapidly increasing young of the commune. The galleries, 

 nurseries, and living-rooms for the numerous males and 

 females are pushed out with such fervor that the ex- 

 cavated pellets rise into heaps and moundlets around 

 the nest gates. In such conditions the overlapping 

 of the new boundaries is inevitable, and in the tense 

 nervous strain and high communal pressure under 



which the work is being pushed, the contact between 



218 



