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GROUP HETEROGYNA. 



Family Formicidae. 



(Ants.) 



Ants are supposed to have had as ancestors cer- 

 tain of the solitary wasps, and in some of the more 

 primitive types of ants, such as the Family Poner- 

 ides (to which bulldog- ants belong), and Family 

 Dorylides (driver and legionary ants), a few of the 

 habits of the wasps are retained. For instance, 

 these primitive ants are usually carnivorous, and 

 feed their larvae on the flesh of insects, etc. ; they 

 hunt for their prey, singly, in many cases ; their 

 nests are usually small with few in a colony (ex- 

 ception to the latter is the- bulldog ant and some 

 of the Dorylides). Many of these primitive 



ants retain the old wasp-habit of spinning cocoons 

 (by the larvae), which custom has been rejected by 

 the more specialised ants. 



Ants can be distinguished from wasps by the pre- 

 sence of a node (Plate i8, Fig. 8, a.) or knob on the 

 petiole of the abdomen. The antennae are elbowed, 

 with the first joint (in the females) greatly elong-ated 

 (Plate i8, Fig. 5.b.) With the exception of a very 

 few parasitic forms, ants are always social in habits. 

 They live in colonies and have the social instincts 

 very highly developed. There are three castes, 

 males, females and workers. In some cases the 



