194 INSECTS. 



nests of Ants present the remarkable phenomenon of 

 being inhabited by various other species of insects, con- 

 cerning many of which there seems to be now no doubt 

 that they are actually kept prisoners by the Ants to serve 

 in various ways to the maintenance of the state. 

 Amongst these are the Aphides, commonly called the 

 cows of the Ants (whence we have given to the latter the 

 name of cattle owners), species which feed on the roots 

 of grass, &c., being plentiful in the nests, whilst others, 

 Leaf-eaters, are sometimes enclosed by the Ants in a kind 

 of earthen gallery constructed on the twig which forms 

 their pasture. Numerous species of Beetles are also well 

 known as inhabitants of ants' nests, and though it seems 

 difficult to ascertain in all cases whether this is in the 

 interest of the Beetles or of the Ants, yet in some there 

 is no doubt that the Ants derive from the Beetles, as from 

 the Aphides, a fluid which serves them as food. Mr. E. 

 Holmes (Zool. 475) saw some large Ked and Black Ants 

 carrying as captives living specimens of Philonthus ; 

 while other observers have seen the ants forcibly pre- 

 venting the escape of certain Beetles from the nest. 

 Woodlice also are found in great numbers in the nests of 

 ants, and whether or not these are amongst the profit- 

 able servants of the commonwealth, there can be little 

 doubt that their residence would be but of short duration 

 if disapproved by their omnivorous little hosts. With 

 regard to the Aphides, and some of the Beetles, the 

 question is put beyond a doubt by the sedulous care taken 

 by the Ants of these herds the eggs of the Aphides 

 receiving attention equal to that paid to their own. 



But yet another element exists in the community of 

 some species of Ants more or less warlike, as are all 

 the social tribes, contending to the death for their terri- 



