Myrmica rubra

Queen: 6–7 mm
• Workers: 4–6 mm
• Monomorphic species — no distinct soldier caste

• Insects: fruit flies, mealworms, crickets, roaches
• Sugar sources: sugar syrup (3:1 water to sugar or honey), honey, maple syrup
• Soft fruits: banana, apple, grape
• Protein jelly: accepted, especially during brood rearing
• Scavenging behavior: readily takes dead insects; remove leftovers to prevent mold

Myrmica rubra is highly active and aggressive, especially during foraging. They display strong recruitment and form dense trails to food sources. Colonies can house multiple queens and grow quickly, making them ideal for keepers interested in dynamic colony expansion and visible surface activity.

They possess a mild sting, which can cause irritation, so caution is advised when handling or opening the formicarium.

• Humidity: Arena: 40–60% | Nest: 60–80%
• Temperature: Arena: 20–26 °C | Nest: 22–27 °C
• Diapause required: 3–4 months at 4–8 °C (essential for long-term health)

This species is known for its flexible nesting habits, high queen tolerance, and intense activity levels. It is one of the few temperate ants that can establish very large polygynous colonies, making it both fascinating and demanding to keep. Ideal for naturalistic terrariums or moist nest setups.