Red-barbed Ant

Fast Facts

Latin name: Formica rufibarbis

Notable feature: Workers have a blackish head and abdomen with a reddish-brown coloured thorax. The thorax has many small erect hairs – which is where this species gets its name from

Conservation Status: Endangered

Where in the UK: Only known from two areas in the UK, St Martin’s (and surrounding islands) in the Isles of Scilly (where it is known locally as the St Martin's Ant) and Chobham Common and Bisley Ranges in Surrey.

Red-barbed Ant (Formica rufibarbis) © Ian Beavis

The Red-barbed Ant (Formica rufibarbis) is a large, native ant. Workers have a blackish head and abdomen which contrasts with a reddish-brown coloured thorax.  The thorax has many small erect hairs – which is where this species gets its name from: rufibarbis means “red-bearded”.

The Red-barbed Ant is a thermophilic species (meaning it requires warmer than “normal” temperatures) therefore it is very fussy about where it lives; preferring bare ground in direct/full sun.

Consequently, the Red-barbed Ant is fond of open heathland and grassland habitats, with loose or sandy soils, patches of bare ground and short vegetation.  The ants excavate their nests in the ground or under stones, and each colony can consist of a few thousand workers and often between 1-3 queens.

The Red-barbed ant is a Priority Species for conservation action in England, it is also considered Endangered in the UK (GB Red List)

It is classed as a common species within continental Europe but there is no data regarding global population trends.

  • Size: Workers measure 4-8mm, queens can measure up to 14mm
  • Life span: Workers may live 1-3 years, whilst queens can live up to 14 years, although it is thought that 10 years would probably be more usual.
  • Diet: Red-barbed Ants feed on other small invertebrates – like moths, spiders, beetles, and other ants. They will also feed on nectar and milk aphids for their sweet honeydew secretions. Red-barbed Ants are known to rob food from other ants whilst foraging.
  • Reproduction: In late June-early July colonies will produce winged males and females.  During courtship, the winged females climb to the top of a blade of grass or plant stem to attract the attention of males by scent.  After mating, new queens try to establish a new colony.  Queens mate only once during their lifetime and store sperm inside their bodies to fertilise eggs for the rest of their lives.
  • When to see: Most active during the summer months, during warm, dry weather, with emergences of new queens taking place in late June/early July.  Nests are usually less active from October-April.
  • Population Trend: The colonies on the UK mainland remain extremely vulnerable to local extinction, especially as their population sizes are now very small.  Colonies in Scilly appear relatively stable.
  • Threats: The main threat to this species is the loss of lowland heathland.  In the past, this habitat was lost to agriculture, forestry, mineral extraction and development.  Most remaining heathland areas are now protected, but remain at risk from lack of management, fires, and nutrient deposition (particularly nitrogen).
  • Fun Fact: Rufibarbis actually means ‘red-bearded’ not red-barbed. The beard is the hairs on the ants thorax.

How you can help: 

Buglife is working to increase awareness of invertebrates and the Red-barbed Ant through specific projects and campaigns but we need your help!

Join a recording scheme and log your finds – send any records/sightings to BWARS or download the iRecord app and get recording!

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