Carpenter ant (male)

Most species are more easily identified from the major workers. Many are large ants; all have antennal bases separated from clypeal border by a space at least equal to the maximum diameter of the scape, mesosomal dorsal profile a continuous curve from pronotum through propodeum (except some subgenus Colobopsis, and these are easily recongnized by the truncate and heavily punctate circumoral portion of the head of majors). (information from BugGuide)