116 Chapter III. 



thus interpreted by writers on popular science, and 

 made to serve as a beautiful proof of animal intelli- 

 gence. This kind of arbitrary misrepresentation of 

 the plainest facts can certainly lay no claim to any 

 scientific value. 



How, then, do ants build their nests? They adapt 

 themselves to given situations and prudently take 

 into account the various circumstances. When in 

 spring a gentle, warm rain begins to render the dry 

 soil soft and manageable, immediately the earth- 

 working ant species are kindled with new zeal for 

 building. These assiduous little animals will then 

 sally forth from their nests by hundreds and place 

 pellets of earth upon pellets to build new galleries and 

 chambers, availing themselves of blades of grass, 

 twigs of heather, pieces of leaves and other natural 

 props as pillars or vaults. For the same purpose such 

 auxiliary materials are also first .dragged to the spot. 

 In this connection the sanguine slavemakers give evi- 

 dence of eminent skill in combining timber-work with 

 masonry. 



It is especially remarkable with earth-working ants, 

 that they accommodate their instincts to the changes 

 of temperature and moisture. This could be ascer- 

 tained constantly in glass nests, in which I kept under 

 observation small colonies of Lasius niger, Tetramo- 

 rium caespitum and Myrmica scabrinodis. If the mois- 

 ture of the nest became too great, the ants would set 

 to work and pile up the earth in the shape of a dome 

 perforated by innumerable openings, making it appear 

 like a sponge ; thus the evaporation of the water was 

 facilitated. But when the moisture decreased too 



