Atta
Atta colombica
Care Guide
Atta colombica is one of the most spectacular leafcutter ants, displaying extreme polymorphism that mirrors the complexity of their society. The queen, a magnificent insect reaching 20–25 mm, is the colony’s sole reproductive powerhouse. Workers range dramatically in size from just 2 mm as the smallest minors to 16 mm in the largest majors and soldiers. This caste system is beautifully specialized: tiny minors tend the fungus gardens and care for brood, media workers cut and transport leaf fragments, while the massive soldiers defend the colony with powerful mandibles.
What truly sets Atta colombica apart is their remarkable fungus-farming lifestyle. These ants do not eat the leaves they cut. Instead, they bring fresh vegetation back to the nest, where it is meticulously cleaned, chewed into a pulp, and used as substrate for a symbiotic fungus. This fungus is the colony’s only food source for the larvae and a critical supplement for the adults. The ants’ diet is therefore indirect: they require a constant supply of fresh, pesticide-free leaves and flowers from a variety of plants, along with occasional protein sources such as insect pieces or specially formulated ant feed. Maintaining a healthy fungus garden demands high humidity and stable temperatures.
Care difficulty
Atta colombica is undeniably an expert-level species, suitable only for experienced keepers with a deep understanding of formiculture. The enormous colony size potential, the delicate fungus symbiosis, and the specific environmental requirements make this a challenging but deeply rewarding project. Success hinges on precise control of temperature and humidity, a steady leaf supply, and meticulous waste management – the colony produces huge piles of spent substrate that must be removed regularly to prevent mould and mites.
Housing
A formicarium for Atta colombica must consist of a spacious, well-ventilated nest area connected to a large foraging arena. The nest should maintain a constant temperature of 24–28°C and humidity of 80–90%. A glass or acrylic setup with a thick substrate layer (such as a mix of soil and sand) allows the ants to excavate their own chambers. The foraging arena needs to be large enough to accommodate the leaf-cutting traffic and should be kept dry to prevent fungus growth outside the nest. A reliable heating cable and a humidifier or regular misting are essential. These ants require total darkness in the nest area; any light disturbance can stress the colony.
First days after purchase
Upon receiving your Atta colombica colony, transfer it carefully into a prepared formicarium that has been pre-heated and humidified. Place the setup in a quiet, vibration-free location and avoid opening the nest for at least 48 hours. During this acclimation period, offer small amounts of fresh leaves (avoid toxic plants like ivy or oleander) and ensure water is always available. Observe the ants’ behaviour from a distance – they will begin exploring and cleaning their new environment. Do not disturb the fungus garden; let the workers adjust and start tending it themselves. Patience is key: this species can take days to resume normal fungus-farming activity. Once you see leaf fragments being carried inside, you’ll know the colony is settling in.
