3 6o THE STUDY OF INSECTS 



The worker ants are so-called because upon this caste devolve all the 

 labors of the colony after they appear on the scene in the foundation 

 chamber. As a rule workers are sterile; but sometimes, as with bees, 

 and wasps, fertile workers occur. It is believed that only males are 

 developed from eggs laid by workers. 



Without attempting to lead the beginning student through the maze 

 of subfamilies, tribes, subgenera and subspecies into which the family of 

 ants has been divided in an effort to classify the different forms, we shall 

 simply discuss a few of the more common ants and some of those that 

 have interesting and rather striking habits of living. 



THE LEGIONARY OR VISITING ANTS 



The members of this subfamily are largely confined to Equatorial 

 Africa and tropical America. The colonies are nomadic, wandering from 

 place to place in search of prey, and forming only temporary nests. 

 Some of the species travel in vast armies and often overrun houses in the 

 tropics, clear out the vermin with which they may be infested, and com- 

 pel the human inhabitants to leave for a time. _ 



The subfamily is represented in our fauna by a single genus, Eciton, 

 species of which occur from North Carolina and Colorado southward. 

 Our species, however, do not form large armies, though they hunt in 

 files like the tropical species, and the colonies of some of the species may 

 consist of thousands of individuals. Some of the species are fond of 

 kidnapping the brood of other ants. The females are wingless and much 

 larger than the workers. The workers are polymorphic. 



THE MYRMICINE ANTS 



In this subfamily the pedicel of the abdomen consists of two segments 

 (Fig. 603). This is a large subfamily; more than half of the species of 



ants found in America north 

 of Mexico belong to it. The 

 following species will serve to 

 illustrate the remarkable differ- 

 ences in habits of its different 

 members. 



The little yellow house-ant, 

 Monomdrium pharaonis. — This 



Fig. 603. - A myrmicid ant. j g ^ species com monly known 



as the " little red ant " although it is light yellow in color. It is the 

 most troublesome of all ants that invade our dwellings. It is only about 

 one-sixteenth of an inch long and often occurs in great numbers. This 

 ant will eat almost any household food but is especially fond of sweet 

 substances. Its nests are often made within the walls of a house in which 

 case it is nearly impossible to destroy them. 



The harvesting ants. — Several genera of myrmicine ants feed on seeds, 

 and as they collect these seeds and store them in their nests they are 

 known as harvesting ants. It was to these ants that Solomon referred. 

 They have also been known as agricultural ants; for it was formerly 

 believed that they sow around their nests seeds of the plants from which 

 they collect the grain that they use. But this has been disproved. 



