BY MARK W. MOFFETT
A very simple instance of a similarity to humans is shown by door-maker ants, Stenamma alas, which find a pebble of a suitable size to serve as the door to the colony entrance. In the left image an army ant has located the unprotected entrance; as soon as this enemy backs away, the guard ant within sticks her head out of the entrance to grab the pebble and move it into place (middle image). The image on the right shows the pebble blocking the doorway. Copyright Mark W. Moffett/Minden Pictures.
ANTS STAKE OUT TERRITORIES, BOLDLY GATHERING food even from our dinner plates, and rear their progeny in elaborate safe havens. Communicative, persistent, hardworking, battle ready, risk-taking, and highly organized, whether they are agronomists, herders, or hunter-gatherers, ants form elaborate labor forces of superb military operatives and diligent homemakers, masters at both protecting and providing for their colonies. Leafcutter ants, for one, have societies decidedly more complicated than any other nonhuman animal, and carry out mass-scale agriculture to boot.