● Castolon [Loc 41] Big Bend N.P., TX USA [el. 660 m / 2164 ft] view location in Google Maps » ● 3/04/10 11:57AM sunny, air temp: 24°C / 76°F Illuminated by the morning sun, a Pogonomyrmex desertorum worker 'freezes' in a defensive posture. This behavior was prompted by intruding Pogonomyrmex rugosus workers - one of which actually attacked a P. desertorum ant (both combatants walked away unharmed). [scroll down for additional notes/references] ADDITIONAL NOTES/REFERENCES: The integument (outer body covering) of these P. desertorum workers was quite translucent. When back-lit by the sun (as can be seen in some of these images), these ants glowed with the most beautiful orange-red color. In some cases, x-ray-like hints of their internal anatomy could be seen as well. - Pogolumina - Pogonomyrmex Harvester Ants of North America