ANTS. 



stationary and populous formicaries, devote a great deal of attention 

 to architecture and work according- to a more or less definite plan, 

 which they skilfully modify to suit the conditions of a specific environ- 

 ment. 



The nest.s of nearly all ants are the result of two different activities, 

 excavation and construction. lloth of these may be simultaneously 

 pursued hv the workers, or either may predominate to the complete 

 exclusion of the other, so that some nests are entirely excavated in soil 

 or wood, whereas others are entirely constructed of soil, paper or silk. 

 As the nests of the latter type resemble those of the social wasps, one 

 might be led to suppose that they represent the original ancestral form 

 and that the excavated are degenerate types, but the prevalence of 

 earthen nests among ants of the most diverse genera in all parts of the 

 world, as well as the occurrence of similar nests among the solitary 

 bees, wasps and Mutillids, would seem to indicate that even the most 



& 



3P 





FIG. 107. Crater of Myrnvecocystus scminifns of the Mojave Desert ; I, natural size. 



(Original. ) 



ancient ants practiced both methods of nesting. In other words, the 

 variable architecture of ants may be an inheritance from presocial 

 ancestors and may have been well-established before these insects 

 came to live in communities. 



The methods employed by worker ants in making their nests are 



