IV INSECTS INHABITING ANTS'-NESTS l8l 



used by other species as attendants, and that the two kinds then 

 live together quite amicably ; and we have also seen that a few 

 ants live in association with other species on terms that are not 

 yet understood. One little ant, Formicoxenus nitidnlus, lives 

 only in the large nests of Formica riifa ; these ants tolerate 

 the little Formicoxenus, which so far as is known does them 

 neither good nor harm. There are also a consideraljle numl)er of 

 species of small ants that are in the habit of choosing the neigh- 

 bourhood of larger species for their dwelling-places ; in some 

 cases the nests are constructed actually within a portion of the 

 edifice of the more powerful species, and the rule then appears 

 to be that these neighbours do not molest one another. Not- 

 withstanding the militant lives that many of them lead, ants 

 cannot be considered as of generally ferocious disposition. 



But the most renmrkaljle point in connection with their 

 toleration consists in the fact that the nests of many species are 

 inhabited by quite a colony of foreign Insects of various Orders ; 

 many of these, being found nowhere else, are spoken of as ants'- 

 nest or Myrmecophilous Insects.^ The relations of ants with 

 other Insects are of the most varied and complex character ; 

 some of their guests live with them on terms of the most intimate 

 association, being indeed absolutely dependent for their existence 

 on the good offices of their hosts ; others of the ants'-nest Insects 

 are enemies, while others are neutral or indifferent to the ants. 

 AVe have already mentioned that the guests migrate in company 

 with their hosts. 



Many species of ants derive a considerable portion of their 

 sustenance from the sweet substances excreted by Aphidae. 

 Ants may constantly be seen occupied with clusters of Aphidae, 

 and it is said that the ingenious little creatures defend from 

 enemies the manufacturers of the sweet-stuff they are so fond of, 

 even going so far as to form barricades and covered places for the 

 isolation and protection of this peculiar kind of cattle ; a few 

 ants keep some of the root -feeding Aphidae in their nests. 

 Coccidae and other Homoptera, which also excrete much matter 

 of a sugary nature, are likewise consorted with by ants ; as are 

 also the larvae of some Itutterflies of the family Lycaenidae ; 

 these latter being believed to furnish to the ants some substance 



1 A Catalogue of Myrmecophilous and Termitophilous Arthropods was pub- 

 lished by Wasinaiin, Berlin 1894. 



