Workers are polymorphic and usually about 4.5–9 mm long; queens are commonly around 9–11 mm.
Fine-art photographic collection
Formica rufa
A mound-building forest engineer whose colony links trees, aphids and soil.
About this species
Red wood ant
Formica rufaLinnaeus, 1761
Information reviewed15 July 2026
Formica rufa is one of Europe’s best-known red wood ants. Colonies build conspicuous thatch mounds from needles, twigs and other plant material over a substantial underground nest. Workers harvest honeydew, hunt arthropods and influence nutrient cycling throughout the surrounding woodland.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Formicidae · Formicinae · Formicini · Formica
Accepted · checked 2026-07-15
Europe and western EurasiaBroad documented localities — not a complete range map.
Widely distributed across Europe and extending eastward into western Eurasia, although closely related red wood ants require careful identification.
Coniferous and mixed woodland, sunny forest edges, rides and clearings where the mound can receive warmth.
Diurnal in suitable weather. Workers maintain trunk routes to aphid colonies and ground trails to prey, nesting material and neighbouring mounds.
Honeydew supplies much of the colony’s carbohydrate, supplemented by captured and scavenged arthropods.
Social organisation varies geographically. Some colonies have one queen and one mound; others contain multiple queens or interconnected nest systems.
What makes this species remarkable?
The mound acts as a solar collector and insulating roof, helping the colony regulate the temperature of brood chambers below.
Workers defend themselves by spraying formic acid, a compound historically named from ants of the genus Formica.
Red wood ant nests create habitat for many specialised beetles and other invertebrates, making the mound a small ecosystem in its own right.
More photographs
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