A busy trail of Monomorium pharaonis pharaoh ants. This species is now among the most pesty house-inhabitating ants worldwide. Icononzo, Tolima, Colombia

Neivamyrmex melanocephalus army ants initiating a live-ant bridge with their own bodies. Here two ants lean against each other while a third starts to climb. Sycamore Canyon, Arizona, USA

Neivamyrmex opacithorax. Army ants carrying brood. Notice how the ants carry their pupae, slung under their bellies in typical army-ant style. Chiricahua Mountains, Arizona, USA