ON ENTOMOLOGY. 37 



whether they worked by night or during the day. All observers, indeed, 

 agree that Ants labour in the night, and a French naturalist is of opinion 

 that they never sleep ; a circumstance which is well ascertained with re- 

 spect to other animals, such as the Shark, which will track a ship in full 

 sail for weeks together. The ingenious historian of English Ants, Gould, 

 says they never intermit their labours by night or by day, except when 

 compelled by excessive rains. It is probable the ancients were mistaken 

 in asserting that they only work when the moon shines ; for like Bees 

 they seem to make no difficulty in building in the dark, their subterranean 

 apartments being as well furnished as the upper stories of their build- 

 ings. 



The BROWN ANT (Formica Brunnea^), one of the smallest of the Ants, 

 is particularly remarkable for the extreme finish of its work. Its body 

 is of a reddish shining colour. The abdomen is of an obscure brown, 

 the scale narrow, of a square form, and slightly scolloped. This Ant, 

 one of the most industrious of its tribe, forms its nest of stories four or 

 five lines in height, (a line is the twelfth part of an old French inch). 

 The partitions are not more than half a line in thickness, and the sub- 

 stance of which they are composed is so finely grained, that the inner 

 walls present one smooth unbroken surface. These stories are not 

 horizontal, they follow the slope of the Ant-hill, and lie one upon 

 another to the ground-floor, which communicates with the subterranean 

 lodges. They are not, however, always arranged with the same regula- 

 rity, for these Ants do not follow an invariable plan ; it appears on 

 the contrary that nature has allowed them a certain latitude in this 

 respect, and that they can, according to circumstances, modify them to 

 their wish ; but, however fantastical their habitations may appear, they 

 are always observed to have been formed by concentrical stories. On 

 examining each story separately, we observe a number of cavities or 

 halls, lodges of narrower dimensions, and long galleries, which serve 

 for general communication. The arched ceilings, covering the most 

 spacious places, are supported either by little columns, slender walls, 

 or by regular buttresses. There are also chambers that have but one 

 entrance communicating with the lower story, and large open spaces, 

 serving as a kind of cross-road, "in which all the streets terminate. Such 

 is the manner in which the habitations of these Ants are constructed. 

 Upon opening them the apartments are commonly found, as well as the 

 large open spaces, filled with adult Ants, and we always observe their pupa: 

 more or less near the surface. This, however, seems regulated by the 

 hour of the day and the temperature, for in this respect these Ants are 

 endowed with great sensibility, and know the degree of heat best adapted 

 for their young. The Ant-hill contains sometimes more than twenty 

 stories in its upper portion, and at least as many under the surface of 

 the ground. By this arrangement the Ants are enabled with the greatest 

 facility to regulate the heat. When a too burning sun overheats their 

 upper apartments, they withdraw their little ones to the bottom of the 



