230 A NATURALIST IN HIMALAYA 



had no longer sufficient strength to propel them 

 further through the air. They fall upon the grass and 

 bushes, then climb out upon the twigs, the leaves, the 

 stones, where they begin forcibly to vibrate their wings. 



Another point to be noted in the nuptial flight is 

 the fact that the termites seem to possess a definite 

 sense of direction. Indeed, from the way they are 

 often seen to move all in the same course, it might 

 almost be said that their flight was in a sense a 

 migration of the swarm. The insects, when they first 

 escape from the nest, seem somewhat confused. They 

 are lost amidst the entanglement of trees and jungle 

 and they flutter aimlessly about. But their instinct 

 is to ascend. Soon they clear the trees, and then it 

 is obvious that all the termites are pursuing the same 

 predestined course. They are free from obstruction 

 in the clear air, and then all move in the same 

 direction and in one uniform flow. It is difficult not 

 to believe that all are guided by some special sense 

 to move in a common line. 



It has often struck me as a remarkable fact that 

 many colonies of termites scattered over a wide area 

 will often give forth their sexual forms all at the 

 same time. I recall the first flight of the season. 

 Many nests, perhaps thirty or forty in number, dis- 

 tributed over an area of about five square miles and 

 through a zone of altitude of 600 feet, were all in 

 eruption at the very selfsame hour. There was no 

 connection between these nests, yet all burst into 

 activity as though it was a single swarm. What force 

 is it that can so influence these termites as to cause a 

 number of widely separated nests to send forth their 

 sexual forms at the same moment of the same day ? 



