i io INSECT ARTIZANS AND THEIR WORK 



it can take advantage of the shelter afforded by 

 a human erection. A colony of this ant had 

 established itself in a mill and had selected as a 

 nesting- place a beam above a staircase. They had 

 found a crack in the wood and used it as a con- 

 venient entrance. From this point they drove 

 tunnels far into the beam, and enlarged parts of 

 these into corridors and chambers. 



The wood cut to small fragments by their jaws 

 was taken back to the entrance and there dropped. 

 But it accumulated in an incriminating heap on a 

 cross-beam only a foot and a half below. So a 

 company of workers was told off to clear it away 

 as it fell. This they did by carrying it bit by bit 

 to the edge of the beam and dropping it over. 

 But this did not get rid of it, for it fell upon the 

 stairs, where it might equally call attention to the 

 presence of the ants. Many of the burrowing 

 Hymenoptera, whether working in wood or masonry, 

 are equally solicitous to remove such evidences of 

 their presence, which might otherwise give the 

 clue to their enemies. A gang of ants was set to 

 work on the stairs to scatter the tell-tale wood- 

 dust farther away. Now these stairs were regularly 

 swept down every morning by the mill-people, and 

 after a time this fact by some means became 

 impressed upon the minds of the ants, for they 

 withdrew the staircase workers and contented them- 

 selves with the dispersal of the debris constantly 

 falling upon the cross-beam. 



These ants are not rapid destroyers like the 



