This large red harvester ant (Pogonomyrmex sp.) has been standing frozen in place to allow the smaller black cone ants (Dorymyrmex sp.) to climb on and begin licking her body surface. Scientists have noted that this behavior seems similar to that of cleaner-fish in coral reefs, but further observation and testing is necessary. After this image was taken, she shook them off before walking away. Photo © Mark W. Moffett/Minden Pictures