Polyergus breviceps
Temperature
20–26 °C
Humidity
50–70%
Colony size
2,000–10,000
Queen size
8–10 mm
Worker size
5–7 mm
Hibernation temp
6 °C
Diet
Care Guide
Polyergus breviceps is a remarkable and highly specialized ant species, known for its parasitic lifestyle and dramatic slave-raiding behavior. Unlike typical ants, a Polyergus queen cannot rear her own brood or even feed herself—she relies entirely on host workers, usually from the genus Formica, to raise her young and maintain the colony. Workers are slender, reddish-brown, and armed with powerful, sickle-shaped mandiles designed not for carrying food, but for piercing the heads of enemy workers during raids. Once the colony is established, workers act as fearless raiders, stealing brood from nearby Formica nests to replenish their host workforce. A mature colony can grow to several thousand individuals, but the queen remains the sole reproductive, measuring up to 10 mm in length, while workers range from 5 to 7 mm.
Care difficulty
Keeping Polyergus breviceps is reserved for experienced ant keepers who are prepared for an advanced challenge. The true difficulty lies in the founding stage: a newly mated queen must be introduced to a brood chamber containing pupae and workers from a compatible Formica host species. Without these, she will quickly starve or fail to lay eggs. Even after successful adoption, the keeper must continuously supply host pupae from a separate Formica colony to maintain the slave workforce. This makes Polyergus one of the most demanding ants to keep, requiring deep knowledge of ant biology and a steady source of host colonies. Their diet includes sugar water and protein sources such as insects, but remember—the workers themselves cannot feed; they rely on host workers to process and distribute food.
Housing
A formicarium for Polyergus must accommodate both the parasite colony and a large number of host workers. The nest should be kept dark, quiet, and stable in temperature between 20 and 26°C, with humidity levels around 50 to 70 percent. Substrate that retains moisture—like natural soil or plaster—is ideal. A separate foraging arena is essential, where you can offer sugar water on cotton balls and protein-rich insects. Hibernation is required: during winter, reduce temperature to around 6°C for several months, mimicking their natural cycle. Plan for ample space, as a mature colony can fill out several connected nest compartments.
First days after purchase
After receiving your Polyergus breviceps colony—typically a queen with a small host workforce—place the setup in a calm, vibration-free location. Resist the urge to disturb them; allow the queen and her host workers to settle into the nest chamber for at least 48 hours. Provide a drop of sugar water and a small protein source, such as a freshly killed fruit fly or cricket piece, near the entrance. Monitor for signs of acceptance: the host workers should begin tending the queen and cleaning the nest. If the colony seems inactive, do not panic—it may take several days for the queen to start laying eggs. Most importantly, prepare your separate Formica host colony ahead of time, as you will soon need to introduce fresh pupae to maintain the slave force. Mastering Polyergus breviceps is a rewarding journey into one of nature's most fascinating parasitic relationships.