THE HABITS OF AXTS IN GENERAL. 



iS 



many other Myrmicinse have at least a single pair of spines on the 

 epinotum, apparently to protect the vulnerable pedicel from the mandi- 

 bles of their enemies. Other species (Cryptoccrus, Catanlaciis, Stnt- 

 inigenys and Mcranophts) can conceal their sensitive antennae in deep 

 grooves or under broad projecting ridges along the sides of the head. 

 But ants do not have to rely altogether on such passive means of 

 defence. The means of direct attack on their enemies are almost as 



FIG. 103. Virgin females and workers of Camponotus aincricauiis. showing five 

 pairs of the latter in the act of feeding by regurgitation. (Photograph by J. G. 

 Hubbard and O. S. Strong.) 



varied and usually more efficacious. The mandibles are the principal 

 weapons and these alone in the larger species of Cainponotns and Atta 

 are sometimes employed with telling effect. In the Myrmicinae and 

 Ponerinse their action is often supplemented by that of a well-devel- 

 oped sting. Many species of Formica spray their enemies with formic 

 acid, or inject it into their victim by moving the gaster forward and 

 centering its tip on the wound made by their mandibles. In battles 

 with other species or aliens of their own species they pull their op- 

 ponents legs or antennae with their mandibles and spray the tense mem- 



