There are four true (Formica rufa group) wood ant species in the UK and several related species. Our true wood ant species are Formica rufa, F. aquilonia, F. lugubris and F. pratensis. Guides that can help you to identify these species can be found in the Links section.
Three related species are considered by the Steering Group due to their woodland habitat, similar appearance to wood ants and rarity. These species are F. exsecta which belongs to the subgenus Coptoformica, F. sanguinea belonging to the subgenus Raptiformica, and F. rufibarbis which belongs to the subgenus Serviformica. Additionally, there is the shining guest ant Formicoxenus nitidulus which lives only in wood ant nests.
Nesting differences between wood ants and other species
The true UK wood ants are all large mound building species. Formica exsecta also builds mounds but these are considerably smaller than wood ant mounds and use different materials such as heather. Our largest UK ant, F. sanguinea, nests in decaying tree stumps, logs, under stones or underground, while F. rufibarbis nests entirely underground.