Myrmecocystus mimicus worker leaving the nest to forage. Sycamore Canyon, Arizona, USA

Myrmecocystus mexicanus. Honeypot ants have an unusual food storage system. Some members of each colony act as living receptacles known as "repletes", these ants become engorged with food and hang from the ceilings of chambers deep underground. Captive colony at the California Academy of Sciences

Army ant colonies typically contain workers of many sizes, each specialized for a different task. Here a Nomamyrmex esenbeckii worker stands guard over a passing column. Gamboa, Panama