u8 INSECT BEHAVIOR 



down a few notes on the strange army ants of South America. 1 



These insects roam the dimly lighted jungles in vast armies, travel- 

 ing about from day to day like bands of gypsies. As they progress, 

 carrying eggs and young with them, they hunt out and capture all 

 insect life that chances in their path. The booty is torn to pieces and 

 then borne to their nest, where the queen and nurses, with the tribe's 

 precious eggs and young, together with a number of guards, remain in 

 safety until the return of the warriors. Scouts are doubtless sent 

 ahead from day to day, whose duty it is to find a safe shelter for the 

 main army, which follows shortly afterwards. 



At six o'clock one morning my attention was attracted by a long thin 

 line of army ants moving hurriedly across the compound. Tracing 

 their line of march I soon found them to be moving in a zigzag course 

 to a hole underneath some blocks of concrete that had originally 

 served as foundations. Evidently they had been moving for several 

 hours, perhaps during the night, for a distinct path two inches or 

 more in width had been trodden smooth by them. 



Here and there a leaf or twig hindered their progress and at other 

 places a depression in the ground called for the unnecessary expendi- 

 ture of energy. To overcome these difficulties, a wonderful sense of 

 duty was displayed by certain members of the tribe, who formed solid 

 living bridges, over which the others passed. Sometimes but a few 

 were necessary to bridge the obstacle, but in other places, dozens and 

 dozens of individuals linked themselves together to form the bridge 

 and complete the road as a smooth, comfortable highway for their 

 tribe. 



The ants traveled from five to eight abreast, never in a wider 

 column, and the moving army reached from the concrete blocks clear 

 across the compound and thence out of sight into the underbrush, a 



1 These observations were made in the jungle near Bartica, British Guiana, in 

 May, 1916. 



