68 ANIMAL INTELLIGENCE. 



in which these wonderful insects enslave insects of another 

 species, which therefore may be said to stand to the ants 

 in the relation of beasts of burden. The case to which I 

 allude is one that is recorded in Perty's ' Intellectual Life 

 of Animals ' (2nd ed. p. 329), and is as follows : 



According to Audubon certain, leaf-bugs are used as slaves 

 by the ants in the Brazilian forests. When these ants want to 

 bring home the leaves which they have bitten off the trees, 

 they do it by means of a column of these bugs, which go in 

 pairs, kept in order on either side by accompanying ants. They 

 compel stragglers to re-enter the ranks, and laggards to keep 

 up by biting them. After the work is done the bugs are shut 

 up within the colony and scantily fed. 



Wars. On the wars of ants a great deal might be said, 

 as the facts of interest in this connection are very nume- 

 rous ; but for the sake of brevity I shall confine myself to 

 giving only a somewhat meagre account. 



One great cause of war is the plundering of ants' nests 

 by the slave-making species. Observers all agree that this 

 plundering is effected by a united march of the whole 

 army composing a nest of the slave-making species, 

 directed against some particular nest of the species which 

 they enslave. According to Lespes and Forel, single scouts 

 or small companies are first sent out from the nest to ex- 

 plore in various directions for a suitable nest to attack. 

 These scouts afterwards serve as guides to the marauding 

 excursion. Forel saw several of these scouts of the species 

 F. rufescens or Amazon carefully inspecting a nest of 

 F. fusca which they had found, investigating especially 

 the entrances. These are purposely made difficult to find 

 by their architects, and it not unfrequently happens that 

 after all precautions and inspections on the part of the 

 invaders, an expedition fails on account of not finding the 

 city gates. 



When the scouts have been successful in discovering a 

 suitable nest to plunder, and have completed their stra- 

 tegical investigations of the locality to their satisfaction, 

 they return straight to their own nest or fortress. Forel 

 has then seen them walking about on the surface of their 

 nest for a long time, as if in consultation, or making up 



