What characteristic describes field ants found in Colorado?

Field ants found in Colorado are commonly characterized by their dark brown or black coloration. This characteristic helps differentiate them from other ant species that may be encountered in the area. The dark pigmentation is typical of many species within the Formica genus, which encompasses many types of field ants, and is a key identifying feature.

Although field ants can vary in size, they are not universally large, which makes size not a definitive characteristic for identifying them. Additionally, field ants do not exclusively nest indoors; they typically create their nests in soil outdoors, in grasslands, or near trees, which distinguishes them from ants that prefer indoor environments. Lastly, distinctive stripes are not a common feature observed in field ants; their coloring generally consists of a solid dark brown or black appearance rather than having any patterned markings.

Overall, the characteristic of being dark brown or black is the most accurate descriptor of field ants in Colorado.