Some of the world's strangest and most interesting beetles live only in ant colonies, skimming from the ants' vast resources to make their living. Here, a Vatesus rove beetle runs in a colony of Eciton army ants. Armenia, Belize

Guard ants from an Azteca colony defend their nest from an army ant raid by pinning down one of the invaders (Eciton hamatum). Jatun Sacha reserve, Napo, Ecuador