Formica fusca
Silky ant
DifficultyBeginner · 3/7
Species comparison
Formica fusca vs Lasius niger
Side by side: difficulty, size, growth, climate, hibernation and nuptial flights, from the data and sources of each species sheet.
Head to head
| Formica fusca | Fact | Lasius niger |
|---|---|---|
| Keeping | ||
| Difficulty | ||
3/7 Beginner | Difficulty | Easier2/7 Beginner |
| Escape risk | ||
Medium | Escape risk | Medium |
| Diet | ||
SugarInsects | Diet | SugarInsects |
| Best nests | ||
Ytong nest · Naturalistic setup · Sandwich nest | Best nests | Sandwich nest · Ytong nest · Acrylic nest |
| Colony | ||
| Growth | ||
Moderate | Growth | Moderate |
| Colony size | ||
Reaches 2,000 workers | Colony size | No data yet |
| Workers | ||
4–7 mm All the same size | Workers | 3–5 mm All the same size |
| Queen | ||
8–10 mm | Queen | 8–9 mm |
| Colony founding | ||
Fully claustral One or more queens | Colony founding | Fully claustral One queen |
| Defense | ||
Bites · Sprays formic acid | Defense | Bites · Sprays formic acid |
| Climate | ||
| Nest temperature | ||
21–25 °C | Nest temperature | 23–25 °C |
| Nest humidity | ||
50–60 % | Nest humidity | 40–60 % |
| Hibernation | ||
5–8 °C Oct – Mar | Hibernation | 8–12 °C Oct – Mar |
| Nuptial flights | ||
Jun – Aug Hot days | Nuptial flights | Jul – Aug Hot days · Calm weather |
| Native range | ||
Europe, Asia | Native range | Europe, Asia |
Size to scale
Formica fusca
Workers · 4–7 mmQueen · 8–10 mmLasius niger
Workers · 3–5 mmQueen · 8–9 mm
Their year side by side
Formica fusca : Hibernation: Oct – Mar, Nuptial flights: Jun – Aug
Lasius niger : Hibernation: Oct – Mar, Nuptial flights: Jul – Aug
Months for temperate Europe and the Mediterranean. The weather decides the exact days, so flights can come earlier or later where you live.
How to tell them apart
Formica fusca
Dull black to dark gray workers with brownish legs that run fast and forage alone, bigger and longer-legged than Lasius niger and less silvery than Formica cinerea. Formica lemani is almost identical and only a microscope (hairs on the pronotum and the legs) tells them apart, so a colony sold as Formica fusca is a best guess within the fusca group, and this sheet describes the species in the strict sense.
- Tip Give the nest a humid chamber and keep the outworld dry. The species comes from dry, open ground, and keepers report that a moist nest with a dry arena works well.
- Watch out Leave a founding queen alone as much as you can. Keepers report queens that ate almost all their larvae after repeated checks and vibrations, so keep the tube dark, still and closed until the first workers appear.
Lasius niger
Small workers that are uniformly dark brown to black with a slightly shiny body, among the commonest ants of gardens, lawns and pavements. Unlike Lasius emarginatus, there is no reddish color on the thorax.
- Tip Use a soil-based sandwich nest to watch them dig their own tunnels, or a white Ytong nest, where the black workers stand out sharply.
- Tip In the wild they milk aphids for honeydew, so they go wild for sweet food: keep honey, sugar water or ant jelly on offer and add a little protein, such as Gammarus or small insects, for the brood.
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