Cephalotes rohweri - Turtle Ant
Arizona, USA

photograph © Alex Wild 2007

Worker dimorphism in Cephalotes turtle ants. Most members of a colony are smaller minor workers (at right), but colonies also contain a number of soldier ants (left).  The function of a large-headed worker caste can vary in different species of ants (for instance, some harvester ants use their majors for milling seeds), but for Cephalotes these soldiers are nest-guarding specialists.  The armored disk on their heads serves as a living door to the nest.

USA AZ Pima Co.: Tucson Mountains
32º03'N 111º06'W 950m. xi.2007.
Ex Parkinsonia Palo Verde tree, Sonoran Desert.

This image is copyrighted by the photographer and cannot be used without permission. To obtain permission to use this image, please email Alex Wild. (alwild (at)  Most of the photographs on are reduced from their original size and compressed for more efficient web transmission.  In some cases, higher quality versions are available.

This image was captured with a Canon EOS 20D, using a Canon MP-E 65mm 1-5x macro lens.