ant, marcher (fauna) known in the jungles of Schendi as 'The Marchers' are these aggressive carnivorous insects. Each is about 2 inches long, with a shiny black exoskeleton and two antennae. Their name is derived from their, apparently seasonal, marches through the jungle in a single column, yards wide and pasangs in length. They may number in the millions, their paths widening to as much as 500 feet when they overtake, swarm over, and devour all flesh, living or dead, in their path. Their bite is extremely painful, but not poisonous. Their victims die from being weakened from relentless attack, being overcome until they are still. Tarl Cabot and the small men, led a column of Marchers, by baiting them with fresh meat, the ants, weaving like a whispering black snake through the jungle until they overran an encampment of the Mamba people, Cabot's intended target.

The column of the marchers was something like a yard wide. I did not know how long it might be. It extended ahead through the jungle and behind through the jungle farther than I could see in either direction. Such columns can be pasangs in length. It is difficult to conjecture the numbers that constitute such a march. Conservatively some dozens of millions might be involved. The column widens only when food is found; then it may spread as widely as five hundred feet in width. Do not try to wade through such a flood. The torrent of hurrying feeders leaves little but bones in its path. 
Book 13, Explorers: pg 399