Scientific illustration of Lasius americanus (Woodland Fuzzy Ant) - showing key identification features including head, thorax, and gaster.

Woodland Fuzzy Ant

Lasius americanus

Polygynous Non-Parasitic Queen No Gamergate
Sci. Name
Lasius americanus
Tribe
Lasiini
Subfamily
Formicinae
Author
Emery, 1893
Common Name
Woodland Fuzzy Ant
Distribution
Found in 2 countries
Nuptial Flight
From May to August
Peak flight Time
18:00
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Introduction

Lasius americanus is a small, dark brown to black ant native to North America. It was recently recognized as a separate species from Lasius alienus in 2018 . Workers have large eyes and lack erect hairs on their antennal scape and hind tibiae, distinguishing them from similar species like Lasius niger . Queens are larger than workers. These ants prefer shaded forest habitats, nesting in soil, rotten logs, and stumps, and can also be found in bogs and wetlands . Colonies are often large with multiple queens, and individual queens disperse to found new colonies independently .

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Status by country, from Kass et al. 2022 & Wong et al. 2023

Native Invasive Introduced (indoor) Intercepted Unknown
Data Sources
Year Range 2000 - 2026

Quick Summary

  • Difficulty: Easy
  • Origin & Habitat: Native to North America, from southern British Columbia to Nova Scotia, south to northern Florida and into southwestern US and Mexico, preferring shaded forest habitats [3].
  • Colony Type: Colonies are polygynous (multiple queens) and can grow very large, with queens dispersing to found new colonies independently [3].
  • Size & Growth:
    • Queen: Size data unavailable from research, inferred from Lasius genus to be approximately 6-8 mm
    • Worker: Size data unavailable from research, inferred from Lasius genus to be approximately 3-4 mm
    • Colony: Up to thousands of workers [3]
    • Growth: Moderate
    • Development: Approximately 6-8 weeks at room temperature, based on typical Lasius genus patterns [3] (Development time may vary with temperature, maintain stable conditions for best results.)
  • Antkeeping:
    • Temperature: Maintain at stable room temperature, roughly 20-24°C, as they are temperate ants [3].
    • Humidity: Keep nest substrate consistently moist but not waterlogged, mimicking their forest habitat [3].
    • Diapause: Yes, require winter diapause for 3-4 months at 5-10°C, inferred from temperate genus patterns [3].
    • Nesting: Prefer nests that mimic natural conditions, such as Y-tong or plaster nests with moist substrate, based on their nesting habits in rotting wood [3].
  • Behavior: Calm and non-aggressive, workers forage actively and tend aphids for honeydew [5]. They are not good climbers but can escape through small gaps, so use barriers like fluon [3].
  • Common Issues: colonies can grow large quickly, ensure adequate space for expansion [3]., multi-queen colonies may have initial queen aggression, but usually settle over time [3]., aphid farming may attract ants to houseplants if nearby [5]., winter diapause is essential, skipping it can weaken the colony., escape prevention is important due to small size, use standard barriers [3].
Nuptial Flight Activity Analysis 314 observations
Jan
Feb
Mar
Apr
36
May
33
Jun
140
Jul
67
Aug
Sep
Oct
Nov
Dec

Lasius americanus exhibits a clear seasonal flight window. Peak flight activity is concentrated in July, with the overall period spanning May to August.

Flight Activity by Hour 314 observations
5
00:00
01:00
02:00
03:00
04:00
05:00
06:00
8
07:00
7
08:00
9
09:00
16
10:00
10
11:00
16
12:00
23
13:00
18
14:00
25
15:00
24
16:00
18
17:00
29
18:00
24
19:00
25
20:00
21
21:00
17
22:00
7
23:00

Lasius americanus nuptial flight activity peaks around 18:00 during the evening. Activity is spread across a 16-hour window (07:00–22:00). A secondary activity peak occurs around 15:00. Times may be influenced by human observation patterns.

Housing and Nest Setup

Lasius americanus does well in standard formicarium setups. Use Y-tong (AAC) or plaster nests that mimic their natural preference for nesting in rotting wood or soil [3]. A test tube setup works for founding colonies, but plan to move them to a larger formicarium within 6-12 months as the colony grows. Keep the outworld simple with easy access to food and water, and ensure escape prevention with barriers on the rim.

Feeding and Diet

These ants are omnivores with a sweet tooth. Offer sugar sources like honey or sugar water, and protein such as small insects [3]. They mutualistically tend aphids for honeydew [5]. Feed protein 2-3 times per week and keep a constant sugar source available. Remove uneaten prey after 24 hours to prevent mold.

Temperature and Seasonal Care

Room temperature around 20-24°C suits them well, with no special heating needed unless your home is very cold [3]. Like all temperate ants, they require a winter diapause: gradually reduce temperature to 5-10°C for 3-4 months in autumn, then return to room temperature in spring [3]. Skipping diapause can weaken the colony over time.

Colony Dynamics

Lasius americanus is polygynous, meaning colonies naturally have multiple queens [1]. Individual queens disperse to found new colonies independently, but established colonies can have many egg-laying queens working together [3]. This makes colonies resilient, but initial queen introductions may involve some aggression that usually resolves.

Behavior and Temperament

These ants are calm and manageable, with workers that actively forage and tend aphids [5]. They do not sting but can spray mild formic acid. They are primarily crepuscular, most active at dawn and dusk, and use standard escape prevention due to their small size [3].

Frequently Asked Questions

Is Lasius americanus a good beginner ant?

Yes, they are excellent for beginners due to their forgiving nature and acceptance of varied foods. The main requirement is providing winter diapause [3].

How long does it take for Lasius americanus to produce first workers?

Expect 6-8 weeks from egg to first worker at room temperature, based on typical Lasius genus patterns [3].

Can I keep multiple Lasius americanus queens together?

Yes, this species is naturally polygynous (multi-queen). You can introduce additional queens to an established colony, though there may be initial aggression that usually resolves [3].

Do Lasius americanus need hibernation?

Yes, they require a winter diapause. Reduce temperature to 5-10°C for 3-4 months during winter, mimicking their natural temperate cycle [3].

What do Lasius americanus eat?

They accept sugar sources like honey or sugar water, and protein such as small insects. They also farm aphids for honeydew [5]. Feed protein 2-3 times per week with constant sugar available.

How big do Lasius americanus colonies get?

Very large, they can reach thousands of workers [3]. Plan for adequate space as the colony grows.

What's the difference between Lasius americanus and Lasius alienus?

Lasius americanus was recently separated from L. alienus in 2018. They are morphologically similar, but L. americanus is the North American species while L. alienus is European/Asian [1][2].

When do Lasius americanus have nuptial flights?

Nuptial flights mostly occur in August, with some records from May to December [3].

How do I identify Lasius americanus?

Look for large eyes and lack of erect hairs on the antenna scape and hind legs. They are dark brown to black, and workers are small [3][4].

When is the nuptial flight of Lasius americanus?

The nuptial flight of Lasius americanus typically occurs From May to August.

What time of day does Lasius americanus fly?

The nuptial flight of Lasius americanus peaks around 18:00 during the evening, with most activity between 07:00 and 22:00. Times may be influenced by human observation patterns.

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References

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This caresheet is licensed under CC BY-SA 4.0 .