--- title: "Army Ant (Eciton burchellii) | AnimalTracks.wiki" description: "A colony of up to a million sisters that clings together as a living nest, then raids the forest floor as a fan-shaped army." image: "https://animaltracks.wiki/images/animals/army-ant-1.webp" published: "2026-10-11" updated: "2026-10-11" --- # Army Ant (*Eciton burchellii*) > **Status**: Checked against 7 sources, listed under Sources below. > **Tagline**: A colony of up to a million sisters that clings together as a living nest, then raids the forest floor as a fan-shaped army. > **Soundtrack Vibe**: Post-Rock & Cinematic Orchestral // MONO, "Everlasting Light" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/3XdNMSoRZdF6cM5pXpZCxQ) > **Vibe Match**: A raid sweeps the forest floor as a fan-shaped army, and large raids can sometimes be more than 30 metres wide. MONO's Everlasting Light grows from a few quiet guitars into the whole band moving as one wide wall of sound. ## Biological Superpowers & Stats - **Taxonomy**: *Eciton burchellii* - **Danger Level**: Medium - **Conservation Status**: Not Evaluated ([IUCN Red List](https://www.iucnredlist.org/)) - **Superpower**: Builds its nest out of the bodies of its own workers - **Habitat**: Tropical forests of Central and South America - **Diet**: Social ants and a wide variety of other arthropods - **Tags**: insect, social-colony, predator, venomous, carnivore, rainforest ## Natural History & Behavior ## Hooks, jaws and up to a million sisters The army ant *Eciton burchellii* lives in the tropical regions of Central and South America, and it prefers heavily forested places. Its workers come in many sizes, from 3 to 12 millimetres long. They have long, hook-shaped jaws, and tiny hooks on their feet that they use to grip each other as they form bridges and nests. A colony can number up to a million sisters. Queens have no wings. The colony's temporary nest, called a bivouac, is built from the bodies of its own members at a protected site such as a hollow tree. > **Egg factory** Within the bivouac, a single queen lays up to 300,000 eggs in a few days. ## A raid that moves house On some days in its settled phase, the colony picks a direction at dawn and raids as a fan-shaped "army" across the forest floor. Large raids can sometimes be more than 30 metres wide. The colony subdues and transports a wide variety of social and non-social arthropods back to the bivouac for consumption. (Arthropods are animals with jointed legs, such as insects and spiders.) More than 50% of its diet is social ant prey. Animal Diversity Web lists tarantulas, scorpions and cockroaches too. The ants subdue prey with stings and pull off legs and antennae with their jaws. Researchers report that this is the only Eciton that preys on large arthropods as well as ants. It also has submajors, an exaggerated transport caste that specialise in carrying non-ant prey. In the nomadic phase that follows, colonies at a study site in Peru raided in one direction for an average of 78 metres and set up a new bivouac almost every night. ## Birds on the payroll Some Neotropical birds follow these raids. They prey on arthropods and small vertebrates flushed from the forest floor by the swarm. One group, the typical antbirds, includes species that appear incapable of foraging independently of swarms. Molecular dating indicates that army-ant-following has persisted in antbirds since the late Miocene. A study of leaf-litter invertebrates in four countries found that, contrary to its popular image, this species did not consistently reduce their biomass. Its impact was concentrated on rich patches of invertebrates. Workers have a well-developed sting. Animal Diversity Web calls it painful. The same account says the species does not frequently come into contact with people. ## Frequently Asked Questions ### How long does an army ant colony stay in one place? It depends on the stage of the colony's cycle. At a study site in Manu National Park, Peru, colonies sat at one bivouac for an average of 21 days. That fits the timing of egg and larval development within the nest. Then a nomadic phase began, with a move to a new bivouac almost every night. *(Source: [Kunhart & Willson 2024]())* ### How many mates does an army ant queen have? A lot. A reanalysis of genetic data found a mean queen-mating frequency of 12.9 males, which the authors called very high. The same study genotyped successive generations of workers from one old queen and found no evidence that she had mated again. *(Source: [Kronauer et al. 2006]())* ### Why do these army ants avoid open pasture? Heat. In Costa Rican forest fragments, colonies avoided entering open pasture in full sun, at 51.3 degrees Celsius, at every edge they met, but readily crossed where artificial shade had been put up. In primary forest, raids avoided spots heated above 43 degrees, though they tolerated 45.5 degrees when prey baits were there. Captive ants held at 43 degrees survived 18.5 minutes. *(Source: [Meisel 2006]())* ## Sources 1. [Eciton burchellii. Animal Diversity Web, University of Michigan.]() 2. [Kunhart & Willson (2024). Intercolony Avoidance Optimizes Foraging in Eciton burchellii Army Ants. Sociobiology.]() 3. [Powell & Franks (2005). Caste evolution and ecology: a special worker for novel prey. Proceedings of the Royal Society B: Biological Sciences.]() 4. [Kaspari et al. (2011). Predation and patchiness in the tropical litter: do swarm-raiding army ants skim the cream or drain the bottle? Journal of Animal Ecology.]() 5. [Brumfield et al. (2007). Phylogenetic conservatism and antiquity of a tropical specialization: Army-ant-following in the typical antbirds (Thamnophilidae). Molecular Phylogenetics and Evolution.]() 6. [Kronauer et al. (2006). A reassessment of the mating system characteristics of the army ant Eciton burchellii. Naturwissenschaften.]() 7. [Meisel (2006). Thermal Ecology Of The Neotropical Army Ant Eciton Burchellii. Ecological Applications.]() *Published October 11, 2026. 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