Myrmica americana

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Nearctic region, native to Canada and the United States. Found from Maine and Quebec west to Manitoba, North Dakota, Colorado, Utah, Nevada, and Arizona, south to Tennessee and North Carolina. Inhabits open areas such as meadows, fields, prairies, grasslands, and woodland edges. Nests in soil, often at the bases of grasses or forbs, sometimes with small chimney-like mounds. ^[1][2][5]
• Colony Type: Polygynous (multiple-queen) colonies with monomorphic workers. Queens mate only once (monandrous). Colonies typically reach around 250 workers. ^[6][7][8]
• Size & Growth:
  • Queen: size data unavailable
  • Worker: 4.5-6.2mm ^[1]
  • Colony: around 250 workers ^[8]
  • Growth: Moderate
  • Development: 6-10 weeks (estimated based on typical Myrmica development) (Brood is present throughout summer months with eggs and larvae still present in early September. Pupae of alates appear in July and August. ^[3])
• Antkeeping:
  • Temperature: Keep at 20-26°C. Workers forage actively between 15-32°C (60-90°F) and become less active above 32°C. A temperature gradient allowing them to choose their preferred zone works well. ^[3]
  • Humidity: Moderate humidity around 50-70%. These ants prefer drier conditions compared to many Myrmica species, they are meadow and old-field specialists. Allow the nest to dry out somewhat between waterings. ^[9][5]
  • Diapause: Yes. This species requires a winter hibernation period. In their native range, reproductives are present in nests from late July until early September, with nuptial flights occurring between late July and mid-October. After flights, colonies need a cold period around 5-10°C for several months to simulate winter. ^[3]
  • Nesting: Use a dry, well-drained nest setup. These ants do well in Y-tong nests or plaster nests with chambers sized appropriately for 200-300 workers. Because they are meadow-nesting ants, avoid overly humid conditions, a relatively dry nest works better than damp setups. Provide a small water tube but don't over-moisten the nesting area. ^[1][10]
• Behavior: Workers are slow-moving but aggressive when threatened. They possess a functional stinger that can penetrate human skin, unusual among North American Myrmica species. They are daytime foragers, actively searching for seeds and small insects. Workers will tend aphids for honeydew and are attracted to protein baits. They are sensitive to disturbance and do not thrive in highly urbanized areas. Escape prevention should be moderate, workers are a good size and not particularly prone to escaping compared to tiny ants. ^[1][11][4]
• Common Issues: colonies often fail if kept too humid, these are dry meadow ants, not rainforest species, hibernation failure is common, colonies need a proper cold period of several months at 5-10°C, slow growth means colonies may appear stagnant during early development, patience is needed, disturbance-sensitive, avoid frequent nest inspections during founding and early colony stages, queens may be killed if the colony is stressed during polygynous establishment

Nest Preferences and Housing

Myrmica americana is a meadow-dwelling species that prefers relatively dry nesting conditions. In the wild, they nest in soil at the bases of grasses or forbs, often building small chimney-like structures around the nest entrance. For captive colonies, use a well-drained nest setup like a Y-tong or plaster nest. Avoid the damp conditions that work well for tropical species, these ants come from open, drier habitats. A small water tube for humidity is sufficient, the nesting area should dry out between waterings. For founding colonies, a standard test tube setup works fine, but keep it in a relatively dry location rather than a humid terrarium. Once the colony reaches 50+ workers, you can move them to a proper formicarium with multiple connected chambers. ^[1][10]

Feeding and Diet

These ants are opportunistic feeders with a varied diet. Workers forage for seeds (particularly panic-grass seeds), small insects, and will tend aphids for honeydew. In captivity, offer a balanced diet of protein and sugars. Good protein sources include small crickets, mealworms, fruit flies, and other small insects. For sugars, provide sugar water, honey, or diluted honey water. They will also accept seeds if offered, though this is more relevant to their natural foraging behavior. Feed protein 2-3 times per week and keep sugar water available constantly. Remove uneaten prey after 24-48 hours to prevent mold. ^[3][1][12]

Temperature and Seasonal Care

Keep your colony at room temperature, ideally between 20-26°C. These ants are active foragers between 15-32°C, becoming less active when temperatures exceed 32°C. In captivity, avoid placing the nest in direct sunlight or near heat sources that would push temperatures above 30°C. A simple room-temperature setup is usually adequate.

Winter care is essential. This species requires a hibernation period to maintain healthy colony cycles. In their native range, reproductives are produced from late summer through early fall, with nuptial flights occurring between late July and mid-October. After this, the colony needs a cold period. During winter, move the colony to an unheated garage or basement where temperatures stay around 5-10°C for 3-4 months. Do not feed during hibernation but provide a small water source. Gradual cooling and warming (over 1-2 weeks each) helps prevent stress. ^[3][1]

Behavior and Temperament

Myrmica americana workers are slower-moving than many ants but are notably aggressive when threatened. Unlike most Myrmica species that are too small to sting humans effectively, this species can deliver a noticeable sting, making them one of the few truly stinging Myrmica in North America. Handle with care.

Workers are daytime foragers and will actively search the outworld for food. They are not skittish and will investigate disturbances. Colonies are polygynous, meaning multiple queens live together harmoniously. This is a relatively long-lived species in the wild, with colonies persisting for many years. Workers are seed dispersers and will collect seeds from the outworld and bring them into the nest, this is normal behavior, not a sign of problems. ^[1][4][3]

Colony Founding

After mating during nuptial flights from late July to mid-October, the queen digs a small chamber and seals the entrance to raise her first workers. This process typically takes 6-10 weeks depending on temperature. After the first workers emerge as nanitics (smaller first workers), the colony expands and the queen resumes egg-laying. Multiple queens may be present in established colonies, which is normal for this polygynous species. ^[3][7]

Frequently Asked Questions

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References