Formica is a genus of ants of the family Formicidae, commonly known as wood ants, mound ants, thatching ants, and field ants. Formica is the type genus of the Formicidae, and of the subfamily Formicinae. The type species of genus Formica is the European red wood ant Formica rufa. Ants of this genus tend to be between 4 and 8 mm long.
- Kingdom: Animalia
- Clade: Euarthropoda
- Class: Insecta
- Order: Hymenoptera
- Family: Formicidae
- Genus: Formica
Bicoloured red and brownish black with variable degree of depth and size of dorsal dark patch on head and promesonotum. Eyes usually with a few microscopic hairs. Long erect hairs more or less abundant on gula, clypeus, dorsum of head, alitrunk, scale and gaster but never on scape nor on posterior border of occiput. Occasional to few suberect hairs on extensor surfaces of hind tibiae and femora. Frontal triangle reflecting light but often in part with micropunctures.
Frons somewhat shining with widely spaced indistinct fine punctures and scattered coarse punctures: coarse and fine punctures widely spaced on disc of first gaster tergite. Funiculus segments two and three always less than twice as long as wide. Length: 4.5-9.0 mm.
The mound-nests of this species are large, isolated and thatched, and a single colony can consist of more than 250,000 individual workers that aggressively defend the territory. Wood ants are carnivorous, and workers carry a wide variety of prey back to the nest along trails that extend throughout the territory. Studies of the southern wood ant have shown that around 60,000 food items are taken to the nest each day.
The workers also tend aphids for the sugary ‘honeydew’ that they exude from the anus; the aphids gain protection from predators in return for this service. Southern wood ant workers have been observed climbing up 30-metre tall Scots pine trees in order to obtain this honeydew, and it has been shown that every season, workers take a massive quarter of a tonne of honeydew back into the colony.