ANTS, BEES AND WASPS 169 



Very curious, too, are the relations existing between the large 

 Wood Ants and two very minute species the Stenamma and the 

 Solenopsis. The Stenammas are found exclusively in the nests 

 of the Wood Ants, and are treated by the rightful owners with 

 the greatest kindness ; the tiny creatures may often be seen 

 frisking and gambolling about the larger ants like a lot of little 

 dogs, and if for some reason the Wood Ants change their nests, 

 the Stenammas always accompany them. 



The Solenopsis, on the other hand, are not harboured willingly 

 by the Wood Ants within their walls. These little robber ants 

 make their home in the walls of the Wood Ants' nest, and con- 

 stantly make raids upon their nurseries, carrying off the helpless 

 larvae as food. The workers give chase, but the audacious little 

 robbers skip hastily back into their diminutive galleries with their 

 booty, where, on account of their size, the enraged Wood Ants 

 are not able to follow them. 



Among the many interesting species of ants inhabiting tropical 

 countries are the Sauba, or Umbrella Ants, of South America. 

 In each nest there are no fewer than five different classes of in- 

 dividuals queens, males, worker minors, which are small ordinary 

 workers, and two types of major Workers, which are very large 

 ants with huge heads, hard and highly polished in one type and 

 hairy in the other. What are the special duties of these curious, 

 large-headed workers is not actually known. Bates, who studied 

 the ways of the Sauba Ants very carefully, was never able to deter- 

 mine what part the major workers took in the work of the colony ; 

 they are, however, most formidable-looking creatures and may 

 perhaps be useful in frightening off raiding ants from other tribes. 



The small Sauba workers appear to do all the work. Parties 

 consisting of several thousand ascend the trees and often almost 

 strip them of their foliage, and in this way the ants do a consider- 

 able amount of damage to the cultivated coffee and orange trees. 

 With their sharp, scissor-like jaws they snip the leaves into semi- 

 circular pieces about the size of a sixpence, and either at once carry 

 the pieces back to the nest or throw them to the ground, when 

 they are at once seized and borne off by another gang of workers. 

 While they are at work regular streams of ants are constantly 

 ascending and descending the tree, while an almost endless pro- 

 cession extends from the tree to the nest, each individual bearing 



