Dinomyrmex gigas are very big ants. You can tell from their name. Imagine a carpenter ant, but three times as big. They live in Borneo in the forests and anyplace with trees and the tree-hoppers they love to farm.
Since they are big powerful ants all out war between colonies is very wasteful. They have a kind of "dance" majors from rival colonies will do to see which ant is "taller."
They stand with their legs as tall as possible and tap each other with antennae.
It seems clear this evolved as a way of measuring if each big major from one colony could be matched by a similar major from the other. If they don't match one group falls back and lets the more powerful ants have the branch. If not they have a peaceful border.
Of course... then there are the sidewalk ants... Tetramorium immigrans who die in huge numbers in their wars... but this is at the end of the summer when many ants die anyway for winter.