ROBBER ECITOXS. 551 



ROBBER ECITONS. 



Another species (the Eciton legionis) has been known to 

 attack other ants' nests for the sake of plunder. Mr. Bates 

 saw an army of them employed on the face of an inclined 

 bank of earth. They were excavating mines to get at the 

 nest of a larger species of ant of the genus Formica. Some 

 were rushing into the passages, others were seen assisting 

 their comrades to lift out the bodies of the formicae, while 

 others were tearing them in pieces their weight being too 

 great for that of a single eciton. A number of earners then 

 seized each a fragment and carried it down the slope. When 

 the naturalist dug into the earth with a small trowel, the 

 eager freebooters rushed in as fast as he excavated, and 

 carried off the ants, so rapidly tearing them in pieces that he 

 had great difficulty in rescuing a few entire specimens. 



The little, ecitons seemed to be divided into parties, some 



A 

 excavating, others carrying away the grains of earth. When 



the shafts became rather deep, the mining parties had to 

 climb up the sides each time they wished to cast out a pellet 

 of earth ; but their work was lightened by their comrades, 

 who stationed themselves at the mouth of the shaft and re- 

 lieved them of their burdens, carrying the particles to a suffi- 

 cient distance from the edge of the hole to prevent them 

 rolling in again. All the work seemed thus to be performed 

 by intelligent co-operation among the host of eager little 

 creatures. Still, there was not a rigid division of labour ; for 

 some of them, whose proceedings he watched, acted at one 

 time as carriers of pellets, and at another as miners, and all 

 shortly afterwards assumed the office of conveyers of the spoil. 

 In about two hours, all the nests of the formicae were rifled. 



