This key is designed for use with worker ants (females).
Worker, queen & male
The diagnostic features do key out queens (females) except for the genus Pheidole, but any reference to size does not apply. Queens may or may not have wings, and posess larger eyes. This key is not suitable for identifying males as they have quite different morphology. Males have wings, a small head with large eyes, and antennae with 13 segments (10 in Tetramorium).