Formica rufibarbis is a European formicine ant of the Formica fusca group. In the classification by Auguste Forel, it is treated in the subgenus Serviformica. F. rufibarbis is subject to a Species Action Plan (SAP) in England, where it is known from only two locations, although it is not considered to be at risk on continental Europe.

Formica is a genus of ants of the family Formicidae, including species commonly known as wood ants, mound ants, thatching ants, and field ants. Formica is the type genus of the Formicidae, and of the subfamily Formicinae. The type species of genus Formica is the European red wood ant Formica rufa. Ants of this genus tend to be between 4 and 8 mm long. Ants belonging to the Formica genus possess a single knob or bump located between their thorax and abdomen. These ants primarily feed on honeydew, a sugary liquid produced by aphids. Formica ants appear to take on a shepherding role with smaller aphids, relocating them to different parts of plants to ensure a continuous food source for the aphids. By doing so, the ants can establish a relatively sustainable honeydew supply for both themselves and their colony.