The Red-barbed ant (Formica rufibarbis) is found in only two locations in the United Kingdom, Chobham Common & Bisley Ranges in Surrey and St Martin's on Scilly; locally it is simply known as the "St Martin's Ant".

The red-barbed ant requires successional heathland habitat and dry, sun exposed habitat for nesting and foraging.

Suitable habitat involves bare ground, short grass and heather mosaics over loose or sandy soils within maritime heath and grassland; as found on St Martin's.  Nests are either excavated in the ground or under stones.

This ant has been described as "probably the rarest animal in Britain" and is classified as endangered; recent evidence and ongoing monitoring suggests that the St Martin's colony is doing well, if not flourishing.

With thanks for the use of St Martin's Ant Image © Ian Condon