Colonies of the rare amblyoponine genus Mystrium have workers of different sizes and body proportions. Laboratory colony at the University of Illinois, originally collected in Maliau Basin, Borneo.
Oecophylla smaragdina weaver ant major worker. Cape Tribulation, Queensland, Australia
In many Pheidole species, one of the primary roles of the major worker is food storage. The swollen abdomen of this ant indicates that her social stomach is full of liquid. Davies Creek, Queensland, Australia.