Aphaenogaster
They are often confused with Pheidole or Pheidologeton. These two have major and minor workers, while Aphaenogaster has only a single worker caste. Pheidole has a 3-segmented club on its antenna. But Aphaenogaster has four segments and a larger body size. Pheidologeton has a 11-segmented antenna, while the antenna in Aphaenogaster is 12-segmented.