BRANCH ARTHROPODA; CLASS INSECTA : THE INSECTS 223 



those hatched in the fall not more than six or eight 

 months. But new ones are hatching while the old ones 

 are dying and the community as a whole always persists. 

 A queen may live several years, perhaps as many as five. 

 She lays about one million eggs a year. 



There are more than two thousand known species of 

 ants (fig. 84), all of which live in communities and show a 

 truly communal life. The ant workers are specially dis- 

 tinguished in structure from the males and females by 

 being wingless, and in numerous species there are two 

 sizes or kinds of workers known as \vorker majors and 

 worker minors. The life-history and communal habits of 

 ants are not so thoroughly known as are those of the 

 honey-bee, but they show even more remarkable speciali- 

 zations. The ant nest or formicary is with most species an 

 elaborate system of underground galleries and chambers, 

 special rooms being used exclusively for certain special 

 purposes, as nurse-rooms, food-storage rooms, etc. The 

 food of ants comprises many animal and vegetable sub- 

 stances, but the favorite food with many species is the 

 4 'honey-dew" secreted by the plant-lice (Aphididae) 

 and scale insects (Coccidae). To obtain this food an ant 

 strokes one of the aphids with its antennae, when the fluid 

 is excreted by the insect and drunk by the ant. In order 

 to have a certain supply oi this food some species of ants 

 care for and defend these defenseless aphids, which have 

 been called the 4< cattle" of the ants. In some cases 

 they are even taken into the ants' nests and food provided 

 for them. "In the Mississippi Valley a certain kind of 

 plant-louse lives on the roots of corn. Its eggs are 

 deposited in the ground in the autumn and hatch the fol- 

 lowing spring before the corn is planted. Now the 

 common little brown ant (Lasius flaws] lives abundantly 

 in the cornfields, and is especially fond of the honey 

 secreted by the corn-root louse. So when the plant-lice 



