308 AFFECTION OF INSECTS FOR THEIR YOUNG. 



moving them from one quarter of the nest to another, as they 

 require a warmer or cooler, a moister or drier atmosphere ; 

 and at intervals brooding over them as if to impart a genial 

 warmth. ^ Experiments have been made to ascertain whether 

 these assiduous nurses could distinguish their eggs if inter- 

 mixed with particles of salt and sugar, which, to an ordinary 

 observer, they very much resemble ; but the result was con- 

 stantly in favour of the sagacity of the ants. They invariably 

 selected the eggs from whatever materials they were mixed 

 with, and re-arranged them as before.^ 



New and more severe labours succeed the birth of the 

 young grubs which are disclosed from the eggs after a few 

 days. The working ants are now almost without remission 

 engaged in supplying their wants and forwarding their growth. 

 Every evening an hour before sunset they regularly remove 

 the whole brood, as well as the eggs and pupge, which in an 

 old nest all require attention at the same time, to cells 

 situated lower down in the earth, where they will be safe 

 from the cold ; and in the morning they as constantly remove 

 them again towards the surface of the nest. If, however, 

 there is a prospect of cold or wet weather, the provident ants 

 forbear on that day transporting their young from the inner 

 cells, aware that their tender frames are unable to withstand 

 an inclement sky. What is particularly worthy of notice in 

 this herculean task, the ants constantly regulate their pro- 

 ceedings by the sun, removing their young according to the 

 earlier or later rising and setting of that luminary. As soon 

 as his first rays begin to shine on the exterior of the nest, the 

 ants that are at the top go below in great haste to rouse their 

 companions, whom they strike with their antennje, or, when 

 they do not seem to comprehend them, drag with their jaws 

 to the summit till a swarm of busy labourers fill every passage. 

 These take up the larvae and pupae, which they hastily trans- 

 port to the upper part of their habitation, where they leave 

 them a quarter of an hour, and then carry them into apart- 

 ments where they are sheltered from the sun's direct rays.^ 



Severe as this constant and unremitted daily labour seems, 



1 De Geer, ii. 1 099. 



2 Gould, 37. 



3 Huber, 74. 



