This formica very similar to F. fusca, except is larger, and much more aggressive. The queens of this ant genus are also very fast and agile. Young colonies are timid, but at around 10 workers they become very aggressive towards anything which moves in their territory. These ants will nest in just about anything but prefer sandy / soil nests.
 
The coloration of this ant is black with a silver sheen. The queens of this species are very sensitive to light once they've gotten used to the nest darkness, red cellophane and a low-level light is required to view them without disturbance. Formica Subsericea queens are normally around 9-12mm while workers from 6-9mm. Hunting and recruiting of workers in this species is interesting as these ants can mark their prey with scent so they can track it and kill it.