BEES, WASPS, ANTS, ETC. 519 



are partly below and ] cully above the natural level of the ground. Although the 

 majority of ants build their nests in the ground, many species cut passages in wood. 

 These usually work in the trunks of trees which are more or less decayed, or in fallen 

 timber. Occasionally the nests are constructed in the timber of buildings. The forms 

 of nests indicated above are the more usual ones in this country. Many striking varia- 

 tions from these are known. The writer observed a nest near Prairie du Chien, Wis., 

 which consisted of a pit, two feet in diameter and three feet deep, with nearly vertical 

 sides. This pit was tilled with small sticks of wood, which were piled to a height of 

 eio-ht inches above the natural level of the ground. Around this heap of sticks was 

 placed the dirt which had been brought up in excavating the pit. The whole resembled 

 an ordinary ant hill, except that the central part consisted only of sticks. These 

 sticks were little twigs, petioles of compound leaves, and straws, varying from one 

 inch to three inches in length. In the pit among these sticks there was almost no 

 earth. 



I have also a fragment of an ants' nest from Arizona, which appears to be made of 

 a sort of paste which very closely resembles the substance used by certain white ants 

 in constructing their nests. 



" In warmer climates the variations are still more numerous. Formica bispinosa, 

 of Cayenne, forms its nest of the cottony matter from the capsules of JBombax. Sykes 

 has described a species of Myrmica which builds in trees and shrubs, the nest consist- 

 ing of thin leaves of cow-dung, arranged like tiles on the roof of a house ; the upper 

 leaf, however, covering the whole. In some cases the nests are very extensive. Bates 

 mentions that while he was at Para an attempt was made to destroy a nest of the 

 sauba ants by blowing into it the fumes of sulphur, and he saw the smoke issue from 

 a great number of holes, some of them not less than seventy yards apart." 



"A community of ants must not be confused with an ant hill in the ordinary 

 sense. Very often, indeed, a community has only one dwelling, and in most species 

 seldom more than three or four. Some, however, form numerous colonies. M. Forel 

 even found a case in which one nest of Formica exsecta had no less than two hundred 

 colonies, and occupied a circular space with a radius of nearly two hundred yards." 



Ants construct roads. Sometimes these are merely beaten paths from which 

 obstacles have been removed, and sometimes they are covered ways. On one occa- 

 sion, when watching a stream of ants (Formica rufa) which was ascending and de- 

 scending a tree, I noticed that the ants came from and returned to a hole in the 



^5 



ground at the base of the tree. On examination this hole proved to be the entrance 

 to a road built beneath a firm layer of partially decayed leaves which covered the 

 ground. This road varied from a half to an inch in width, and extended to an ant hill 

 at least one hundred feet from the tree. I carefully uncovered the road for its entire 

 length. The general course of it was direct, although there were numerous windings. 

 That this road was a veritable tunnel, and not merely a way which had been covered 

 by the falling of leaves, was shown by the fact that, after the layer of leaves had been 

 removed, the road appeared as a ditch cut in the soil. 



The food of ants consists of various sweet substances, as nectar, juices of fruit, 

 and the excretions of certain insects. They also feed largely upon other insects. It 

 is only necessary to watch an ant hill for a short time to be able to see ants bringing 

 home insects for food. I have seen ants in- cotton fields destroying great numbers of 

 cotton worms. The importance of ants as destroyers of noxious insects is appre- 

 ciated in Prussia, where the government has issued a decree against the destruction of 



