THE SOCIAL INSECTS 



of feeding themselves. At the most they can take a little 

 liquid food if they happen to find a conveniently placed drop. 

 The amazons are thus clearly degenerate, and can live for 

 only a short time in the absence of their slaves. There are 

 few things more remarkable in an amazon colony than the 

 sight of large groups of workers, much bigger and more 

 formidable than their slaves, spending the whole day doing 

 nothing but occasionally cleaning themselves or soliciting the 

 slaves for food. 



The small slaves, which are usually workers of Formica 

 fusca, construct and enlarge the nest, forage for food, feed 

 the amazons and tend all the brood. This is in marked 

 contrast to Formica sanguinea, whose slaves never leave the 

 nest but only tend the brood. 



During the height of the summer the amazons make a 

 number of slave-raids. When engaged in this way their whole 

 behaviour alters. There is a period of intense activity when 

 the amazons gather round the mouth of the nest, and then 

 they all start off in a rather compact army. Normally they 

 go straight to some nest of the slave species, and it seems that, 

 as in Formica sanguinea, the way must be surveyed in pre- 

 paration, though the army is not led by any particular 

 individual. When they arrive at the slave nest they pour in 

 through the entrance and begin to come out with grubs or 

 cocoons. Adult ants are not attacked unless they resist, 

 when they are killed instantly by being pierced with the 

 sickle-like mandibles. The return with prey is more leisurely 

 and not made in a compact group. Much of the prey serves 

 later as food for the colony, but some of the cocoons are kept 

 to produce new slaves. 



When the amazon queen founds a new colony, after her 

 marriage flight, she enters a colony of Formica fusca or one 

 of the similar species. She kills the queen but does not molest 



162 



