Up the River of Tapirs 167 



black one, moving with a well-extended front. These 

 ants, sometimes called army-ants, like the driver-ants of 

 Africa, move in big bodies and destroy or make prey of 

 every living thing that is unable or unwilling to get out 

 of their path in time. They run fast, and everything 

 runs away from their advance. Insects form theii chief 

 prey; and the most dangerous and aggressive lower-life 

 creatures make astonishingly little resistance to them. 

 Miller's attention was first attracted to this army of ants 

 by noticing a big centiped, nine or ten inches long, trying 

 to flee before them. A number of ants were biting it, 

 and it writhed at each bite, but did not try to use its 

 long curved jaws against its assailants. On other occa- 

 sions he saw big scorpions and big hairy spiders trying 

 to escape in the same way, and showing the same help- 

 less inability to injure their ravenous foes, or to defend 

 themselves. The ants climb trees to a great height, much 

 higher than most birds' nests, and at once kill and tear 

 to pieces any fledglings in the nests they reach. But they 

 are not as common as some writers seem to imagine ; days 

 may elapse before their armies are encountered, and 

 doubtless most nests are never visited or threatened by 

 them. In some instances it seems likely that the birds 

 save themselves and their young in other ways. Some 

 nests are inaccessible. From others it is probable that 

 the parents remove the young. Miller once, in Guiana, 

 had been watching for some days a nest of ant-wrens 

 which contained young. Going thither one morning, he 

 found the tree, and the nest itself, swarming with forag- 

 ing ants. He at first thought that the fledglings had 

 been devoured, but he soon saw the parents, only about 



