Army ants are highly organized social insects known for their aggressive predatory behavior and collective foraging. Unlike many other ant species, they do not build permanent nests, instead forming temporary shelters from their own bodies as they move across landscapes. This nomadic lifestyle is driven by their need to find substantial amounts of food to sustain their large colonies, which can number in the millions. Their coordinated hunting strategies allow them to overwhelm prey, making them significant predators in their ecosystems.
Main Food Sources
The primary components of an army ant’s diet are other insects and arthropods. These include insect larvae, pupae, and eggs, along with adult insects such as grasshoppers, beetles, and spiders. Many species, particularly those that forage underground, specialize in ground-dwelling arthropods and their immature stages. Some army ant species are also known to specialize in raiding the nests of other ant species and wasps to consume their offspring.
A single army ant colony can consume over 100,000 arthropods daily. This substantial intake is necessary to feed their large populations and support the developing brood. While individual worker ants are often unable to consume solid food, they ingest liquids from their prey, which is then transported back to the colony to feed the queen and larvae.
Hunting Tactics
Army ants employ characteristic swarm raids to acquire their food. Thousands to millions of ants spontaneously stream out from their temporary bivouacs, moving across the forest floor in coordinated columns or broad fronts. This coordinated effort allows them to overwhelm prey too large for individual ants to subdue.
Chemical communication, primarily through pheromone trails, is central to their hunting strategy. Lead worker ants lay down chemical trails for others to follow, guiding the foraging party and directing the attack. Soldier ants, larger in size with powerful mandibles, protect the borders of the raiding party and assist in subduing prey. Once prey is located, ants swarm and immobilize it, often using their strong mandibles to slice and tear it apart. Some species also use a dissolving acid on their victims to break down flesh into a consumable liquid.
Beyond the Usual Prey
While insects and arthropods constitute their staple diet, army ants can also consume less common or opportunistic food sources. They may prey on earthworms, scorpions, and occasionally small vertebrates like lizards, snakes, and bird nestlings if encountered and overwhelmed. These instances are secondary to their primary insectivorous diet, often occurring when such animals are unable to escape the advancing swarm.
Some specialized species, such as Cheliomyrmex andicola, are adept at consuming vertebrate flesh, with claw-shaped jaws suited for this prey. African driver ants (Dorylus species) have mandibles that can butcher vertebrate flesh and attack larger animals. They may also scavenge carrion, an opportunistic behavior rather than a primary hunting focus. Some species, such as those in the genus Labidus, include fruit in their diet.