Formica selysi
Temperature
20–26 °C
Humidity
50–70%
Colony size
2,000–10,000
Queen size
8–10 mm
Worker size
4–7 mm
Hibernation temp
6 °C
Diet
Care Guide
Formica selysi is a medium-sized, energetic species native to southern Europe and Central Asia, known for its remarkable speed and aggressive foraging behavior. These ants form monogynous colonies (a single queen per nest) that can grow to several thousand workers, creating a bustling and highly active community. The queen measures 8–10 mm, while workers range from 4–7 mm, exhibiting modest size variation but no extreme polymorphism. Their most distinctive trait is their rapid, almost frantic movements when disturbed, a sign of their keen defensive instincts and efficient hunting strategy. In the wild, they are swift predators of small insects and also tend aphids for honeydew, making them a versatile species that thrives on a mixed diet of protein and sugars.
Care difficulty
Keeping Formica selysi is best suited for intermediate keepers who already have some experience with fast-growing, active ant species. Their claustral founding phase is straightforward—the queen seals herself in a brood chamber after mating and does not need feeding until her first workers emerge—but once the colony grows, they demand regular feeding and a stable environment. The colony’s high activity level means they will quickly explore any space you provide, so you must plan for expansion. They also require a winter dormancy period (hibernation) at around 6°C for several months, which is essential for long-term health and future breeding.
Housing
A large, well-ventilated formicarium with an attached foraging area is ideal. The nest must maintain a temperature gradient between 20°C and 26°C, with humidity levels of 50–70%—regular moistening of the nest substrate is necessary, especially during brood development. Because Formica selysi is highly active and will escape given the chance, ensure all connections are escape-proof and that the foraging arena has a secure lid or barrier. They are not particularly sensitive to vibrations or light, but a quiet location free from constant disturbance will help the colony grow more steadily. Provide a constant supply of insect protein (crickets, mealworms, or roaches) and sugar water or honey water; they also appreciate natural honeydew if available.
First days after purchase
As soon as your Formica selysi colony arrives, place the containing tube or test tube setup into the prepared formicarium’s foraging area and cover the nest zone with a dark cloth to reduce stress. Keep the colony undisturbed for at least 24–48 hours to allow the ants to acclimate. After this period, offer a small drop of sugar water and a tiny piece of insect protein near the nest entrance. Observe their feeding response—healthy workers will quickly swarm the food and carry it back inside. Maintain steady moisture in the nest tube and check that the queen is showing normal behavior (brood care, moving eggs). Do not attempt to move them into a different container for the first week; let them settle naturally. Once they have established, you can gradually integrate them into the full formicarium.