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 sanguinea , or common large red ant, and consist of 
sand or clay, 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. Lincecum, 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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