Chap. VII. SLAVE-MAKING INSTINCT. 215 



has been described by Mr. Smith. Although so small a species, 

 it is very com'ageoiis, and I have seen it ferociously attack other 

 ants. In one instance I found to my surprise an independent 

 connnunity of F. llava under a stone beneath a nest of the 

 slave-making F. sanguinea ; and when I had accidentally dis- 

 turbed both n«'sts, tlie little ants attacked their big neighbors 

 with surprising courage. Now I was curious to ascertain wheth- 

 er F. sanguinea could distinguish the pupae of F. fusca, which 

 they habitually make into slaves, from those of the little and 

 furious F, llava, which they rarely capture, and it was evident 

 that they did at once distinguish them; for we have seen that 

 they eagerly and instantly seized the pupre of F. fusca, whereas 

 they were much terrified when they came across the pupa?, or 

 even the earth from the nest, of F. flava, and cjuickly ran away ; 

 but in about a quarter of an hour, shortly after all the little 

 yellow ants had crawled away, they took heart and carried off 

 the pupaj. 



One evening I visited another community of F. sanguinea, 

 and found a number of these ants returning home and entering 

 their nests, carrying the dead bodies of F. fusca (showing that 

 it was not a migration) and numerous pupa?. I traced a long 

 file of ants burdened Avith booty, for about forty yards, back to 

 a very thick clump of heath, whence I saw the last individual of 

 F. sanguinea emerge, carrying a pupa ; but I was not able to 

 find the desolated nest in the thick heath. The nest, h^wnver, 

 must have been close at hand, for two or three individuals of 

 F. fusca were rushing al^out in the greatest agitation, and one 

 was perched motionless with its own pupa in its mouth on the 

 top of a spray of heath, an image of despair, over its ravaged 

 liome. 



Such are the facts, though tliey did not need confirmation 

 by me, in regard to the wonderful instinct of making slaves. 

 Let it be observed what a contrast the instinctive habits of F. 

 sanguinea jiresent with those of the Continental F. rufescens. 

 The latter does not build its own nest, does not determine its 

 own migrations, does not collect food for itself or its young, 

 and cannot even feed itself: it is absolutely dependent on its 

 numerous slaves. Formica sanguinea, on the other hand, pos- 

 sesses much fewer slaves, a!id in the early part of the summer 

 extremely few : the mastcTS determine when and where a new 

 nest shall be formed, and, when they migrate, the masters carry 

 the slaves. Both in Switzerland and England the slaves seem 

 to have the exclusive care of the lurviu, and the masters alono 



