Cyphomyrmex rimosus
Temperature
24–28 °C
Humidity
75–90%
Colony size
100–500
Queen size
3–4 mm
Worker size
2–3 mm
Diet
Care Guide
Cyphomyrmex rimosus belongs to the fungus‑growing tribe Attini, making it a smaller, more delicate cousin of the well‑known leafcutter ants. The queen measures just 3–4 mm, while workers range from 2–3 mm – petite even by ant standards. Despite their tiny size, these ants practice a sophisticated form of agriculture. Rather than cutting fresh leaves, they forage for dead plant material, fruit fragments, and insect frass, which they bring back to the nest to cultivate a specialised fungus garden. The colony, which typically numbers between 100 and 500 workers, relies entirely on this fungus as its primary food source. In addition, the ants will accept small pieces of fruit and occasional protein sources like crushed insects, but the fungus must always be maintained.
Care difficulty
Keeping Cyphomyrmex rimosus is considered advanced, primarily because of the need to sustain their fungal symbiont. Unlike seed‑eating species, these ants cannot thrive on simple pantry items; the keeper must provide a constant, suitable substrate for the fungus. The nest environment must remain consistently warm and extremely humid – temperatures between 24–28°C and humidity levels of 75–90% are essential. Any drop in humidity can quickly cause the fungus to desiccate and collapse, leading to colony loss. For this reason, experienced keepers who already understand humidity control and fungal husbandry will find these ants rewarding, while beginners may struggle.
Housing
A formicarium for Cyphomyrmex rimosus must accommodate both the ants and their fungus garden. The nest chamber should have good ventilation but also high moisture retention – a substrate like plaster or clay that can be regularly moistened works well. Avoid materials that dry out rapidly. Since these ants do not hibernate, they can be kept active year‑round, but the nest must never be allowed to dry out completely. It is also wise to provide a separate foraging arena where you can add the organic matter needed for fungus cultivation. Keep the nest area dark and minimise vibrations; these ants are sensitive to disturbance, especially when the colony is small.
First days after purchase
Upon receiving your Cyphomyrmex rimosus colony, place the formicarium in a quiet, dimly lit location. Allow the ants at least a day to settle without disturbance. Check that the fungus garden is intact and that humidity is high – the substrate should feel damp but not waterlogged. Offer a small piece of soft fruit (e.g., apple) and a tiny protein source such as a crushed cricket leg. Observe whether workers are actively tending the fungus and moving substrate. Avoid opening the nest frequently; instead, monitor through the glass or acrylic. With patience and careful humidity management, these agriculturalists will soon begin expanding their fungal farm, revealing one of the most fascinating behaviours in the ant world.