The "army" in their name refers to their predatory raids. Without a central leader or visual coordination, the ants use pheromone trails to organize into massive fan-shaped columns.
Furthermore, by clearing out massive amounts of debris and controlling the populations of other insects, they act as a reset button for the forest floor, ensuring biodiversity by preventing any one species from dominating the leaf litter. The Lesson of the Colony army ant
Unlike most ants, army ants ( Eciton burchellii and similar species) do not build underground nests of dirt or wood. Instead, they are nomadic. Their "home" is a —a living structure composed entirely of the ants' own bodies. By interlocking their legs and mandibles, hundreds of thousands of workers create a hanging nest that regulates temperature and protects the queen and larvae. The "army" in their name refers to their predatory raids