Thatching-ant
Guides
Formica obscuripes
Western Thatching Ant
Formica obscuripes, the western thatching ant, is a North American mound-building ant known for constructing large thatched nests from plant materials. Colonies can contain up to 40,000 workers and demonstrate complex social organization including behavioral constancy in worker task performance. The species employs hybrid foraging strategies combining pheromone-marked columns with visual and path integration navigation. It maintains defensive mutualisms with aphids and exhibits aggressive territorial behavior including the use of formic acid against intruders and competing vegetation.
Formica oreas
Hill Mound Ant
Formica oreas is a thatching ant in the Formica rufa species group, known for constructing conspicuous mound nests from plant material. The species is an aggressive predator with well-documented chemical defense mechanisms. Workers produce alarm-recruitment pheromones from their poison gland (formic acid) and Dufour's gland (hydrocarbons) to coordinate nest defense. These semiochemicals are exploited by blacklegged ticks (Ixodes scapularis) as predator avoidance cues, representing a documented case of eavesdropping on predator communication signals.