22 A NATURALIST IN HIMALAYA 



large Messor soldiers then came to the entrance of 

 their nest, and one took up the position of guard on 

 either side of the opening. Whenever a worker of 

 the other species approached within an inch of the 

 entrance, one of the soldiers would instantly rush 

 forward and endeavour to seize the intruder ; but 

 although the soldiers were too heavy and clumsy to 

 capture the agile Acantholepis, yet they succeeded in 

 guarding their nest successfully against the host of 

 excited migrants. None of the smaller workers at- 

 tempted an attack, but continued to perform their 

 domestic duties under the safe protection of the two 

 soldiers. Thus do the soldiers of the species M. 

 himalayanus perform distinct and specialized duties 

 in regard to the protection of the nest. 



The following is another instance of the division of 

 labour in this community. A number of the ants were 

 excavating a nest from beneath a small stone situated 

 against a sloping bank. The earth which they removed 

 had accumulated into a heap, and numbers of the 

 workers were engaged in carrying their loads from 

 the inside of the nest on to the surface of the heap. 

 The surface of the mound thus formed was flat, and the 

 extremity furthest from the nest formed a miniature 

 precipice overhanging the ground below. I observed 

 that the ants emerging from the nest never threw their 

 loads down the precipice, but laid them on the surface 

 of the mound. The ants, however, had stationed a 

 special worker on the brink of the precipice, and, as 

 fast as the excavating workers deposited their loads 

 on the flat summit of the mound, they were taken over 

 by this special worker, carried by her to the edge and 

 pitched 4own the precipice. This appeared to be the 



