Formica lugubris, also known as the hairy wood ant is common in the forests of the United Kingdom. Similar to other species of wood ants (genus Formica), Formica lugubris can be identified by a fringe of hairs that reaches down to their eyes. They can reach sizes of up to 12 mm long, and they live in massive colonies. Colonies consist of workers and queen ants, all of which are carnivores.