INSTINCTS OF HARVESTING ANTS 31 



What can we say of an instinct such as this, at one 

 time so sure a guide, at another time so utterly at 

 fault ? I withdraw the ant returning from its cemetery 

 six inches on its track and it soon regains its road ; 

 I transfer it the same distance from its nest and it 

 wanders aimlessly as in a dream. In one case the 

 sense is certain, in the other it is lost. But why, 

 I know not. The sense of smell though wonderful 

 is comprehensible ; the sense of direction is an 

 inexplicable mystery. 



That many ants are able to communicate intelligence 

 one to the other is an undoubted fact. I shall later 

 illustrate the high degree to which this faculty has 

 been developed in another species found in the valley. 

 The harvesters, however, can claim the power ot 

 communication only in a moderate extent. The one 

 kind of information, and that a most important one, 

 which these ants can undoubtedly communicate to 

 each other is the presence of danger. When one ant 

 in the society is alarmed, the news spreads amongst 

 all the members with extraordinary rapidity. On one 

 occasion, when the ants had collected into little groups 

 of ten to twenty individuals and were sheltering from 

 the rain in a dull torpid state, I touched a solitary ant 

 that was resting quite separate from any of the groups. 

 The ant hurried away in alarm to the nearest group. 

 As soon as it touched one of the ants in the group 

 with its antennae, the information was rapidly spread 

 from individual to individual and the whole group 

 broke up in wild alarm. As each excited ant reached 

 another group the same flurry ensued, and in a very 

 short space of time all the torpid groups were dashing 

 about in disorderly commotion. Thus a single ant 



