200 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



it is one of the most fascinating and stimulating books of 

 natural history ever written. 



About five thousand kinds of ants are known, all of which 

 live socially in small or large communities comprising three 

 usually well-distinguished types of individuals, namely, fertile 

 females, or queens, males, or drones, and sterile females, or 

 workers. The workers are wingless, while the males and queens 

 are winged, although the queens pull off their wings after 

 mating. There may be a certain further amount of structural 

 differentiation within a species in that the workers may be of 

 two or three different types. The general appearance of ants 

 is so characteristic that they are readily distinguished from all 

 other insects, and their extraordinarily developed communal 

 life is more or less familiarly known to every observer or reader. 

 To the economic zoologist, however, ants do not present any 

 very large importance. A few kinds of house ants can be 

 extremely troublesome and a few garden-infesting kinds do 

 some injury to vegetables and fruits. Their greatest damage 

 probably is done indirectly, through their habits of protecting 

 and caring for plant-lice (aphids), from which they obtain 

 their favorite food of "honey-dew." All of these protected 

 aphids are injurious to plants because they suck their sap. 



The ant communities live in nests comprising a number of 

 irregular chambers and galleries, most of the species living 

 underground, although a considerable part of the nest may be 

 above the normal ground surface, built up as a mound or hill- 

 side, of more or less symmetry and greater or less size. This 

 part above ground may be composed chiefly or wholly of soil 

 brought up from below surface, or may be partly or wholly 

 made up of bits of wood, grass and weed stems, chaff or pine- 

 needles. The nest may be made under a stone or log, or be 

 established in a wholly exposed place. Most ants keep their 

 nest fairly near the surface, but a few mine deeply. Still other 

 species tunnel out their corridors and rooms in wood an old 

 log or stump, dry branches, or what not while yet others live 

 in the stems of plants, in old plant-galls, in hollow thorns and 

 spines; finally a few make nests of delicate paper or tie leaves 

 together with silken threads. Very wonderful are some of the 



