When on the march the insect world flees before them, and, as you have seen in the beginning of the chapter, I had the approach of a bashikouay army heralded to me by this means. Wherever they go they make a clean sweep, even ascending to the top of many small trees in search of birds’ nests, and to devour the young of caterpillars. They pursue their poor prey with an unrelenting fury, and seem to be animated with the genius of destruction. Their manner of attack is by an impetuous _leap_. Instantly the strong pincers are fastened, and they only let go when the piece seized upon gives way. If they were large they would certainly be the most fearful creature man could ever encounter, and they would destroy all the living creatures of the forest. When on their line of march they often find little streams—which of course are not very wide; they throw themselves across and form a bridge, a living bridge, connected by two trees or high bushes on opposite sides of the stream. This is done with great care, and is effected by a great number of ants, each of which clings with his fore-claws to his next neighbor’s body or hind-claws. Thus they form a high, safe bridge, over which the whole vast regiment marches in regular order. If disturbed, or if the bridge is broken by the violence of some animal, they instantly attack the offender with the greatest animosity. To find the place for these bridges must require a good deal of sagacity. By one way or another they find a spot where on each side there is a branch of a tree, almost always a dead one, that has fallen on the ground, and which overlaps the stream. Often in falling this tree has broken in two pieces, and the piece on the other side almost joins it. The branch on the further side must be lower on the ground, so that, as they form the bridge, they begin it from the higher side. [Illustration: THE BASHIKOUAY ANT, MAGNIFIED TO TWICE ITS NATURAL SIZE.] [Sidenote: _VARIOUS SPECIES._]