94 TWO CHAPTERS OX ANTS. 



other species are easily injured by the for- 

 ceps. Among these are the two large spe- 

 cies of carpenter-ant before mentioned, which 

 work in stumps or Mien timber. These ants 

 all have well-developed teeth, and the shell- 

 like covering enveloping the body is much 

 thinner than that of the harvesting-ant. 



If it be urged that hard wood will not 

 wear down the teeth like mining in the 

 sandy soil, I can bring forward another 

 member of this family (Camponotus socius, 

 Roger), which lives in the ground, and whose 

 mining and tunnelling are on a much more 

 extensive scale than those of the harvesting- 

 ant. The formicary of this Camponotus often 

 extends over several square rods, with large 

 entrances at various points, all connected 

 by underground galleries, requiring a great 

 amount of labor to construct them; while 

 each colony of the harvesting-ant has a close 

 compact nest or formicary, requiring much 

 less work to construct it. The worker ma- 

 jor of Camponotus socius is very large larger 

 than the soldier of the harvesting-ant. The 

 formicaries of the two species are often in 

 close contact, so that the nature of the soil 

 is precisely the same. I have examined 

 thousands of Camponotus socius, and in no 

 instance have I found the teeth worn down. 



