Nest Building in Leaf-Cutting Ants: Behavioral Mechanisms and Adaptive Value

Leaf-cutting ants, which comprise more than 50 species distributed from Patagonia to North America, build the largest nests among ants. Workers forage plant fragments to cultivate a symbiotic fungus inside underground chambers, which serves as the primary food source for the colony. While digging the nest, workers respond to local cues such as soil temperature, moisture, and CO₂ levels, resulting in the emergence of a nest architecture that provides a proper environment for fungus growth. Leaf-cutting ants have species-specific nest architectures, which evolved from a basal design consisting of a vertical tunnel and a few interconnected chambers. Some species developed, in addition, architectural innovations aimed at the control of both hygiene and nest climate, including waste chambers, ventilatory turrets, and a nest thatch. A fine-tuned climate control is achieved by the relocation of fungus gardens within the nest following the workers' environmental preferences and by nesting plasticity.