CARNIVOROUS ANTS 55 



species on the side of a bank bordering a field of 

 Indian corn, and noticed that the earth which the ants 

 were throwing out had accumulated in the form of 

 a steep cone extending base downward from the mouth 

 of the nest. It was like a landslip down the side of 

 a hill, and, whenever an ant emerged with its little 

 load of earth and ran out on to the apex of the cone, 

 the loose sheet of earth crumbled away beneath its 

 little feet and it tumbled down the slippery cone. The 

 position of the ants at each exit from the nest resembled 

 that of a man on the snow-slope of a mountain in 

 imminent danger of losing his foothold and rolling 

 down into the valley. 



The next evening, on visiting the nest, I found that 

 the ants were adopting a wonderful and most ingenious 

 method of overcoming their difficulties by making the 

 ground so firm and resisting beneath their feet as to 

 prevent their fall. One energetic worker had been 

 detailed to collect pebbles from the foot of the cone, 

 to carry them up the slope and build a level platform 

 of stones over the apex of the cone just outside the 

 mouth of the nest. As the workers emerged they 

 now no longer moved over the crumbling and slippery 

 earth, but over the firm and secure platform of 

 pebbles. 



I watched the ant in this strange, intelligent labour. 

 Down the slope it hurried to search for a suitable 

 pebble. Backwards and forwards amongst the larger 

 fragments, which by their weight had rolled to the 

 very foot of the slope, it rushed about in enthusiastic 

 haste. It was now digging in the ground for suitable 

 fragments, now turning over the pebbles, now testing 

 the weight of the larger stQnes or attempting to drag 



