Formicidae 511 



of the new one. In the winter the semi-dormant ants, far below the 

 earth's surface, may be dug out and placed in a correspondingly deep hole 

 in a new locality and covered with fragments of the old mound. In the 

 summer the material of the mound may be carried off in grain sacks with 

 such ants as stay with it, while most of the population may be con- 

 centrated in jars or old milk cans by taking advantage of the habit of 

 the ant to seize hold of any new object. That is, bits of rags are 

 thrown on the mound and when attacked by ants, shaken over the mouth 

 of an open can or paper bag and again used until most of the visible ants 

 are captured. After that, digging in the mound reveals the young, which 

 should be carefully taken up by means of a spoon and placed in preserve 

 jars without crushing. In the winter time, the queens are rather readily 

 found jammed with workers in some deep-lying galleries beneath the 

 mound, but in summer they readily escape capture. In order to study 

 these ants in the laboratory itself, various modifications of formicaries 

 in use for smaller ants may be made. Large horizontal and also vertical 

 formicaries are made with large sheets of glass (old windshields will 

 serve) separated by rather thick strips of wood or by plaster of Paris, 

 with holes and plugs for access to the interior. 



To supply somewhat natural conditions for the ants in the laboratory 

 three-dimensional formicaries were made from old tubs, alcohol barrels 

 sawed in two, or even packing boxes, filled with clay at bottom and 

 friable earth on top. When the colony is placed in such a tub the ants 

 dig in and become established, but wander out and are lost or destroyed 

 unless restrained. They are kept in by supporting the tub on bricks in 

 a shallow metal-lined box containing water. Even then ants fall into 

 the moat about the tub and after they have thrown various fragments 

 onto the water, will eventually make a bridge across the moat unless the 

 water surface is kept clean. Vaseline may be smeared over the outer 

 wall of the moat to diminish the loss of prisoners. Such a tub colony sur- 

 vived several years, fed with earthworms, insects, and honey, and watered 

 with occasional rains from a watering pot. On the surface of the earth, 

 which the ants raised into a mound, twigs with honey-dew insects were 

 placed for observation and various frames were erected with contrivances 

 to present food to wandering ants which could be marked with colored 

 shellac before returning to the mound for the reinforcements needed to 

 manage large masses of food. 



A large mound was established in a dark room designed for experi- 

 ments. Placed on the floor, this populous mound was surrounded by a 

 water moat 3 inches wide made by soldering zinc strips to form a rec- 

 tangular trough 6 feet long and wide, 3 inches high and broad, filled with 

 water. Within the enclosed 36 square feet of area, the ants carried on 

 their architectural work, their feeding, and their disposal of the dead for 



