Wars and Slavery in the Animal Kingdom. 79 



Formica species and rear them as slaves even when 

 they are given to them by man. ForeP and myself 

 have made various experiments on this point 

 with artificial observation nests kept in a room and 

 with nests found in free nature. It may suffice to 

 mention one of them. In the summer of 1895, several 

 times in succession I took a large bag of worker 

 cocoons from a huge ant hill of F. rufa and emptied it 

 in the neighborhood of a densely populated sanguinea 

 nest,^ which had but a few fuscas as slaves. In a few 

 minutes the sanguine ants had put to flight the thousands 

 of rufas contained in the bag with the cocoons and parts 

 of the nest, had snatched the cocoons from the mouths 

 of the fleeing rufas and began to ransack whatever I 

 had brought of the hostile' nest. For hours after, hun- 

 dreds of these white "ant-eggs" were seen wandering 

 from the plundered nest to the den of the robbers and 

 mysteriously disappearing therein. By far the greater 

 number of the rufa cocoons were reared by the san- 

 guineas. This artificially mixed colony numbered, in 

 1896, about 5,000 san guineas and 8,000 rufas. The 

 latter were generally busy building on the surface of 

 the nest and had soon given it the appearance of a 

 true nifa nest. At the least disturbance, however, 

 thousands of light-red san guineas would dart out from 

 the interior to defend their common home; and thus 

 the supposed rufa nest was turned into a sanguinea 

 nest as if by magic. Because ants know no other home 

 than that in which they have developed from the 

 cocoon, these rufas, although they are in the majority, 



1) "Fourmi- de la Suisse," p. 258 ff. 

 *) Colony No. 39 of the statistical map. 



