INSTINCTS OF HARVESTING ANTS 41 



nest, I thought that, after all, the ants stood to gain as 

 much as they lost, for instead of having to make a 

 journey with the refuse chaff to some little distance 

 from the nest, they need only come to the mouth of 

 the nest and from there drop their burdens to the 

 ground. But as I watched, to my surprise I saw an 

 ant emerge from the nest with a fragment of chaff, 

 but, instead of dropping it to the ground, the foolish 

 insect actually climbed for nine inches down the 

 vertical wall, and then lowering its burden against the 

 clay, let it fall down into the ravine. All the other 

 ants engaged in the work of removing refuse con- 

 scientiously followed its example. It is an excellent 

 instinct that compels these creatures to carry the 

 fragments of refuse a short distance clear of the nest, 

 but such was their lack of intelligence that, when the 

 nest was situated on the face of a perpendicular wall, 

 they were quite unable to modify that habit though it 

 involved them in much unnecessary labour. Yet in a 

 similarly situated nest further up the ravine their folly 

 became almost ludicrous, for here, not only did they 

 make no use of the position of the nest for dropping 

 refuse to the ground, but they actually carried the 

 fragments vertically up the wall until they reached a 

 horizontal ledge almost a foot above them, and there 

 they carefully deposited each fragment of chaff, which 

 was almost immediately blown away by the wind. I 

 cannot attribute to creatures that so wastefully expend 

 their energy in the performance of such foolish acts 

 as these anything more than the faintest spark of 

 intelligence. 



Other ants behave with equal folly when their nest 

 is similarly situated. I have observed litde ants of the 



