Narrow headed ant Formica exsecta

The narrow headed ant is a wood ant, which are the largest type of ant in Britain. They are red and dark brown wood ant with a single segment as a “waist.” Queens and reproductive males have well-developed thoraxes and are larger than the worker ants. Worker ants can be distinguished from other wood ants by a charateristic deep notch on the back of the ant’s head. Males have obvious sex organs protruding from the abdomen.

Behaviour

The narrow headed ant is an aggressive species, sometimes attacking larger wood ants. Winged ants fly in July and August. Nests usually hold more than one queen and about a thousand workers. Workers take a sweet liquid known as “honeydew” from aphids and also scavenge other invertebrates. Nest mounds are typically 25cm high, 30cm in diameter and built in sunny locations to maximise warmth. The main threats to this species are road developments and intensive land management, such as that of management for game.

Size

Length: 10 to 12mm

Status

Listed as Endangered on the Great Britain Red List and is a UKBAP priority species.

Distribution

Found only in the Scottish Highlands and parts of southern England.

When to see

July – August

Facts

  • Reproductive females, known as queens, shed their wings after mating.

Common name

Narrow headed ant

Species name

Formica exsecta

IUCN Red List status

N/a

When to see in Scotland

July – August

Where to see in Scotland

There have been no sightings of narrow-headed ants on Scottish Wildlife Trust reserves.

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