OUTLINES OF ENTOMOLOGY. 41 



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rendering the insects upon which their young are to feed helpless to 

 escape or resist, and yet not fatally injured so that they would spoil 

 before being required for food. 



CHAPTER XI. 

 Order hymenoptera. Section Aculeata. 



ANTS. 



[Fig. 17.] 



Worker Aut. Formica. 



All the typical ants (composing the tribe Heterogyna) are social 

 Insects which rank next to and in some respects exceed the bees in 

 their manifestations of ingenuity and intelligence. 



A colony — termed a formicarium — as in the case of other social in- 

 sects, always contains three and occasionally four distinct forms, males, 

 females, workers, and sometimes soldiers or some other distinct class. 

 The males and females at a certain period in their development acquire 

 wings and arise from the nest. After sporting together for a time in the 

 open air the females return to the nest or perhaps originate new col- 

 onies, and divest themselves of their wings, as these appendages in the 

 retired life they henceforth lead, would be not only useless but cumber- 

 some. The male ants, which are much smaller than the females, hav- 

 ing once left the nest never return to it, and are usually short-lived. 

 The workers and soldiers, which are imperfectly developed females, 

 never acquire wings, and differ from the perfect individuals in having 

 the joints of the thorax less compactly united, and the basal and some- 

 times the succeeding joint of the abdomen formed on top, into a sort of 

 scale or node. The head is generally more or less triangular, the anten- 

 nae are long and elbowed, and seem to be the organs of communication 



