is a morphologically diverse genus of small myrmicine ants found worldwide. Colonies often live in tight spaces and can survive long periods of dearth. Some species are known as acorn ants or rock ants for their nesting habits.
The prickly little beast on the right is a millipede in the genus Polyxenus. I found several of these living in the brood nest of a Temnothorax rugatulus ant, where they were probably scavenging on the ant's refuse.
Huachuca Mountains, Arizona, USA
