1410 THE STORY OF THE UNIVERSE 



their nests, keeping them, in fact, just as we do cows. 

 Moreover, they collect the eggs in the autumn and 

 tend them through the winter (when they are of no 

 use) with the same care as their own, so as to have 

 a supply of young Aphides in the spring. This is one 

 of the most remarkable facts I know in the whole 

 history of animal life. One species of red ant does 

 no work for itself, but makes slaves of a black kind, 

 which then do everything for their masters. The 

 slave makers will not even put food into their own 

 mouths, but would starve in the midst of plenty if 

 they had not a slave to feed them. I found, how- 

 ever, that I could keep them in life and health for 

 months if I gave them a slave for an hour or two in 

 a week to clean and feed them. 



Ants also keep a variety of beetles and other insects 

 in their nests. Some of these produce a secretion 

 which is licked by the ants as they do the honeydew ; 

 there are others, however, which have not yet been 

 shown to be of any use to the ants, and yet are rarely, 

 if ever, found, excepting in ants' nests. That the ants 

 have some reason for tolerating their presence seems 

 clear, because they readily attack any unwelcome in- 

 truder; but what that reason is, we do not yet know. 

 If these insects are to be regarded. as the domestic 

 animals of the ants, then we must admit that the ants 

 possess more domestic animals than we do. 



M. Lespes, who regards these insects as true do- 

 mestic animals, has recorded some interesting obser- 

 vations on the relations between one of them (Clavi- 

 ger Duvalii) and the ants (Lasius niger) with which 

 it lives. This species of Claviger is never met with 



