166 KANSAS ACADEMY OF SCIENCE. 



ing near, as the roots would penetrate the underground galleries and 

 chambers. Water, after a rain, would follow down the roots and de- 

 stroy the nest. 



The mounds are covered with any surrounding available material, 

 such as pebbles, gravel, cinders, and dirt pellets. Along the railroads 

 they are covered with cinders, bits of coal and ballast. Many of the 

 mounds on the town site at Wallace, Kan., as illustrated in plates 

 XXV and XXVII, were covered with bits of glass, mortar, nails, etc., 

 this material being available on account of many of the houses having 

 been torn down. True, some of the covering is brought up from 

 below, as they are excavating for the underground galleries and cham- 

 bers. However, the most of it is gathered out around the nest, as it 

 is of the nature of the surrounding material. The purpose of this 

 ■gravelly covering is to protect the mound from the outside elements, 

 •such as rain and wind. The slope of the mound is usually as steep 

 as the gravelly covering will permit. This covering is from one-half 

 ■to one inch thick. 



It is surprising with what ease these ants will handle the pebbles, 

 which they seize with their outstretched mandibles, and carry over 

 the rough pebbles, to the very summit of the mound without once 

 stopping to rest. Some of the pebbles are at least eight times the 

 weight of the ant carrying them. Yet, with the head elevated, and hold- 

 ing the pebble well to the front, the little worker carries the burden 

 to the desired place, somewhere on the surface of the mound. The,y 

 work entirely without the assistance of another. Many times a worker, 

 after working hard and long to carry a pebble, finds, on reaching the 

 mound, that the load is too heavy with which to ascend. While she 

 is working away with the pebble at the base of the mound, other ants 

 pass within touching distance, but never stop to assist, or even to as- 

 ■certain what the trouble is. And thus the disappointed ant must 

 leave the precious pebble at the base of the mound. 



Many of the cones have just the single opening, while others have 

 two and three. One exceptionally large one had as many as eight. 

 The position of the gates is usually about one-third of the distance 

 from the base of the mound to the summit. There is no uniformity 

 in regard to the direction of the gates. However, the tendency seems 

 to be to the east, southeast, and south. These gates, which are fun- 

 nel-shaped openings through the gravelly covering, extend downward 

 a short distance and communicate with the galleries and chambers 

 found in the interior of the mound, and even several feet beneath the 

 mound. The gates are opened and closed every morning and even- 

 ing, the time varying with the season of the year. In the summer 

 they are usually opened between eight and nine o'clock. They begin 



