Red-barbed Ant - the Red-barbed ant (Formica rufibarbis) is most distinguishable by the large amounts of red colouration on the head and alitrunk. In Britain, the red-barbed ant is possibly the rarest resident animal in mainland Britain confined to Surrey heathland and the Isles of Scilly, where it is known as the 'St Martin's ant'. There is only one colony now known on Chobham Common and it is all one gender, lacking a queen, putting the species at high risk of being lost in mainland Britain.
The Red-barbed ants nests are completely within the ground, usually in sandy banks and nest chambers situated about a foot beneath the surface and are accessible only from a single entrance. This makes the locating of colonies very difficult, so it is possible that the tiny numbers of recorded colonies constitute an under-representation.
Worker ants possess a remarkable sense of sight and will proceed to their nest entrance in a very straight line even if major obstacles are placed to disrupt their path. Foraging red-barbed ants will also challenge other ant species for food, gripping on and tussling until it can decamp with the prey.
Colonies usually contain one to three queens. Eggs are first laid early in the new year and colonies reach a maximum size of around 500 worker ants. Alates (reproductions of a social insect) emerge in late June to early July.
Like other Servifusca, this species is subject to raids by dulotic species such as Formica sanguinea and Polyergus rufescens where their ranges coalesce. In Britain this only takes place at Chobham in the case of the former (the latter does not occur in the country).
The Red-barbed ant is on the red list in Britain, although it is not considered at risk in continental Europe.