Here’s a question for my myrmecologist readers. Has anyone published observations of ritualized fighting among colonies of Pogonomyrmex harvester ants? I know such behavior was famously studied by Bert Hoelldobler in Myrmecocystus, and that ritual combat has been noted in Camponotus and Iridomyrmex. The reason I ask is that the pogos in my front yard back in Tucson would engage in what looks like the same sort of behavior. Ants from opposing colonies stand up on little stilt-legs and push each other about without anyone getting hurt.
I suspect these non-lethal ways of establishing territorial boundaries may be more common among ants than we’d thought, and if no one has recorded ritual combat in Pogonomyrmex it should be worth publishing a note somewhere. More photos below the fold.
Myrmecos Blog 
I’ve got photos of Aphaenogaster cockerelli engaging in what looks similar to the ritualized combat you describe – pushing, pulling, stilt-legged standing. The interactions would sometimes escalate beyond posturing, with groups of Aphaenogasters ‘spread-eagling’ single Aphaenogasters occasionally.