Lasius nearcticus
Temperature
20–26 °C
Humidity
55–75%
Colony size
3,000–15,000
Queen size
7–9 mm
Worker size
3–4.5 mm
Hibernation temp
6 °C
Diet
Care Guide
Lasius nearcticus is a charming and adaptable species native to North America, often found in open woodlands and meadows. These ants are monomorphic, meaning workers are uniform in size, ranging from 3 to 4.5 mm, while the queen measures a modest 7 to 9 mm. Colonies are founded claustrally—the queen seals herself in a chamber and rears the first workers without ever leaving for food, relying entirely on her stored fat reserves and wing muscles. Once established, a mature colony can grow to between 3,000 and 15,000 workers, forming a bustling but manageable community.
What makes Lasius nearcticus particularly interesting is their strong association with root-feeding aphids and other honeydew-producing insects. In the wild, they tend these “herds” and collect the sugary secretions as a primary carbohydrate source. In captivity, they readily accept sugar water and honey in addition to their protein needs—provided via small insects like fruit flies, crickets, or mealworms. This balanced diet keeps the colony healthy and active. They are diligent foragers and will eagerly explore their surroundings, making them a joy to observe.
Care difficulty
Keeping Lasius nearcticus is considered intermediate, primarily because they require a dedicated overwintering period. Their need for a true hibernation at around 6°C for several months is essential for the queen’s egg-laying cycle and colony health. Without this cold dormancy, the colony may decline or fail to thrive. For keepers in temperate climates, a refrigerator or cool cellar works well. Outside of hibernation, their care is straightforward: stable temperatures between 20 and 26°C and moderate humidity of 55 to 75% are ideal. A moistened area in the nest should be provided, while the outworld remains drier.
Housing
A formicarium for Lasius nearcticus should offer a mix of humid nesting chambers and a dry foraging arena. They appreciate structures that mimic soil or rotting wood, such as a plaster or clay nest with small, dark chambers. As the colony grows, the nest must be expandable or connected to additional modules. These ants are not particularly aggressive but can be skittish, so a connection tube system allows for easy feeding and cleaning without disturbing the nest. Provide a reliable water source in the outworld, and offer sugar water in a shallow dish or test tube feeder. Insects should be offered once or twice a week; remove any leftovers to prevent mold.
First days after purchase
When your Lasius nearcticus colony arrives, transfer it gently into its new formicarium using the supplied tube or container. Place the setup in a quiet, dimly lit spot and resist the urge to peek constantly. For the first few days, allow the ants to acclimate without disturbance—cover the nest area to block light. Ensure the water supply is full and that a small drop of sugar water is available near the entrance. Watch for signs of nesting activity, such as excavation or brood clustering, which indicate they are settling in. After a week, you can begin offering small prey items. With patience and proper hibernation, this species will reward you with a lively, productive colony that brings a little piece of North American woodland right into your home.