Scottish wood ant Formica aquilonia (Aberfoyle)

A frosty walk in Aberfoyle forest and came across several ants nests.

Tolerates denser shade than the other
species, but also generally prefers sunny
patches within Scots pine and birch
woodlands. Will persist in small
woodlands, under small groups of trees,
in dense regeneration or even-aged
plantations and along the rides after
complete canopy closure. Ability to
withstand deeper shade is thought to be
related to colony organisation.

A good link here on wood ants 

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