THE BUTTERFLY ij.) 



stroking each other, they can tell each other of the whereabouts 

 of food, of the approach of an invading army, or of the need 

 of aid. They cUstinguish members of their own community 

 from those of other communities, and recognize one of their 

 numljer, even after a long aljsence, and receive it back to the 

 colony with demonstrations as of joy. 



Social Life of Ants. — To illustrate the complex social life of ants, 

 a more detailed account is here given of certain interesting species. 

 Certain ants, such for instance as our Formica'' sajiguinca,' a rust-red 

 species often found living beneath large, flat stones, make slaves of 

 another species of ant which (a curious coincidence) is a dark-colored 

 species. In some slave-making species (the Amazons) the jaws have 

 become so modified to aid in capturing slaves that they are aljso- 

 lutely dependent upon their slaves for food, and would die sur- 

 rounded by food were none of their slaves at hand to feed them. 



The Harvester Ant. — One of our most interesting ants is the 

 Agricultural Ant of Texas {Pogonomynnex ^ molefaciens ^) . This ant 

 makes a circular clearing about its mound, upon which it allows only 

 one species of grass to grow. The ripe seeds of the grass arc carefully 

 harvested by the ants and stored within the chamlsers of their mound. 

 From time to time such seeds as h.a^-e spoiled in the granaries are 

 brought out and thrown away. During rainy seasons, some of these 

 seeds germinate as though j^lanted (Fig. 60). 



The army ants, of which there are several species, occur in great 

 numbers in tropical South America. Like man)^ other species which 

 live by hunting, they migrate from a locality after having exhausted 

 it of their food. While on the march, the young of the species are 

 transported by some of the adults. When an army of these ants 

 approaches a place, every living animal endeavors to escape. The 

 jjreeding birds must be on the alert to pick off the advance guard to 

 prevent them from returning to the army with news of the presence 

 of nestlings. Insects of all sorts, young and old, fall a ready prey to 



^ Ant. ^ pogon , hQ^rd \ myrmcx, ajit. 



2 Sanguis, blood, referiing to color. ^ Mole or mound builder. 



