[IMAGE 1 of 3] Pausing for a few seconds, this Pogonomyrmex imberbiculus worker investigates a piece of plant matter. She moved on without retrieving the object. This image was captured about 0.6 m / 2 feet away from this ant's tiny nest.
These ants are quite difficult to image. On both of the occasions during this trip (Nov. 2010) that I observed P. imberbiculus, there were no more than two workers on the surface at any given time. They move along at a modest but steady pace, and pause infrequently (and very briefly).