132 ROMANCE OF THE INSECT WORLD CHAP. 



are probably less particular in the selection of their 

 building materials than F. brunnea. The hillock of 



the ash-coloured ant always 

 presents thick walls, the stories 

 are well marked, the chambers 

 large with vaulted ceilings, and 

 the galleries strictly speaking 

 are large oval passages. The 

 chambers and galleries rest 

 upon a solid basis, arising from 

 the mode of heightening the 

 habitation. The existing roof 

 is covered with a thick layer 

 of fresh moist clay, converting 

 it into a floor for the pro- 

 posed story. On this the 

 builders proceed to plan the 

 erection intended, forming 



FIG. 19. Agricultural Ants cutting . . r , , . 



down obtruding grass; from CaVltlCS OI almOSt CQUal depth 

 McCook. . . 



in it, and raising the inter- 

 vening elevations into wall-like partitions, having 

 first reduced the foundations to a due thick- 

 ness and removed the loose earth from the floors 

 of the apartments. Lastly, all is closed in. The 

 muscular power and energy of these ants are 

 truly amazing, as exemplified by the observations 

 of Huber, who watched a single worker make 

 and roof in a gallery two to three inches long, 

 she herself fetching, and kneading, and placing 

 her own materials, and the interior was rendered 

 perfectly concave, a day's work, in propor- 

 tion to her size, far beyond the power of man. 



