Camponotus ulcerosus
Arizona, USA

photograph © Alex Wild 2006
A major worker of Camponotus ulcerosus, one of the most distinctive North American Camponotus species.  The function of the large head is unknown, but this ant probably serves as a living door, plugging the nest entrance with her head.
USA AZ Cochise Co.: 5km SSE Sierra Vista, Ramsey Canyon Road.  1460m 31º28.02´N 110º15.87´W 
22.iv.2006   Prosopis woodland, Sonoran desert.  Nest under stone.
A. L. Wild #AW2818, voucher specimens deposited at ALWC.

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, with a Canon 65/2.8 MPE 1-5x Macro lens.