is a genus of arboreal ants with a primarily Holarctic, northern Neotropical, and Indo-Australian distribution. Many species have major workers with enlarged heads for blocking the nest entrances.
Colobopsis impressa is a small arboreal ant whose minor workers (right) mimic Crematogaster acrobat ants. The major workers (left) serve as living doors, plugging nest entrances with an enlarged head.
Laboratory colony at the University of Central Florida, USA