316 HALF HOURS WITH INSECTS. [Packard. 



hood. These nests occupy a surface of many square metres, 

 and their depth varies from one to two metres." (Sumichrast.) 



The exact height of these ant hills is not stated. The 

 largest earthen nests of which we have any account are those 

 described by the Jesuit Dobrizhoffer and alluded to by West- 

 wood in his " Introduction to the Modern Classification of 

 Insects." The conical nests of these ants, which abound in 

 the plains of Paraguay, are said to be as hard as stone and 

 " three or four ells high." A Flemish, English and French 

 ell are three, five and six quarters of a yard respectively ; 

 which measurement is intended by the Portuguese writer or 

 Prof. Westwood is not stated. By English measurement 

 the hills would be about twelve feet high. This is the only 

 case where the hills of the ants emulate in size those of the 

 Termites. Our largest native nests are made by the For- 

 mica sangicijiea, or common large red ant, and consist of 

 sand or claj^ according to the nature of the ground. Un- 

 doubtedly the object of the ants in making the hills is to 

 keep the water out of their burrows, but in Labrador, where 

 it rains nearly every other day, I have observed that this 

 or an allied species makes no hillocks, but lives exclusively 

 in underground passages. 



Another kind of ant attains a still higher degree of civili- 

 zation. The Agricultural ant of Texas, studied for so many 

 years by Dr. Liucecura, is said by him (in the "American 

 Naturalist") to build paved cities and construct roads. In 

 a year and a half from the time the colony begins, the 

 ants previously living concealed beneath the surface, appear 

 above and "clear away the grass, herbage and other litter 

 to the distance of three or four feet around the entrance to 

 their city, and construct a pavement, .... consisting of a 

 pretty hard crust about half an inch thick," formed of coarse 

 sand and grit. These pavements would be inundated in the 

 rainy season, hence, " at least six months previous to the 

 coming of the rain," they begin to build mounds rising a 



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