2 TWO DESTKUCTIVPi ANTS. 



generally in sandy soil. The more compact soils seem to be un- 

 favorable for their construction. A very common location for a 

 colony is a sandy promontory, well lighted by the sun, in the bend 

 of a river. 



The large irregular mounds are due to the leveling by the Avind 

 and rains of the circular ridges of sand, brought from beneath 

 the surface, which surround the openings. Consequently, each of 

 the mounds is an indication of the activity of the ants for many years. 

 Beneath these mounds are numerous chambers connected by narrow 

 passages, and there may be direct connection by these channels over 

 an area of several hundred square feet. 



The habits of this insect have attracted great attention from scien- 

 tists and others. The ants cut the leaves from trees and carry 

 them to the nests. Each leaf is finely divided and made into small 

 pellets. In this Avork the mandibles and legs of the ants are utilized. 

 The small masses are placed upon the so-called fungus garden, where 

 they furnish a growing medium for the growth of a fungus which 

 furnishes the colony with food. As the supply of fungus is con- 

 sumed the ants add to the old mass, so that eventually the nests are 

 found to contain large spongy formations on the outer portion of 

 which the slender threads of the fungus are growing. Evidently 

 the ants exercise great care in preventing the contamination of the 

 fungus garden by any but the sole species of fungus that is utilized. 



The ant is active throughout the gi'eater part of the year. In 

 fact, it becomes quiet for only a very short time when the winter 

 cold is most severe. It is disinclined to work during very hot 

 weather. During the cooler months its activity extends through- 

 out the day, but during the summer it is confined to the night. The 

 distance over Avhich foraging expeditions take place may be 200 

 yards or even more. Practically all species of plants seem to be 

 suitable for food, although it is noticeable that only one species is 

 attacked at a time. Dr. W. M. AAlieeler, who has made very careful 

 studies of these ants, has noted that the same colony may feed upon 

 a wide variety of plants at different times, but he never observed 

 the individuals of a colony collecting different varieties at the same 

 time.^ Among cultivated crops, cotton, corn, fruit trees, sorghum, 

 and many others are attacked. Among wild plants, forest trees are 

 favored, and frequently the Spanish moss is used. The various 

 species of oaks seem to be more or less immune, either on account 

 of the texture of the leaves or the tannic acid they contain. This 

 immunity is by no means absolute, however, as Dr. '\'\nieeler and Mr. 

 J. D. Mitchell have observed the ants making use of such rough 

 leaves as those of the live oak. 



1 Wheeler, W. M. The Fungus-Grt)wing Ants of North America. Bui. Amer. Mus. Nat. 

 Hist., vol. 23, Article XXXI, pp. 729-742. 



