Fighting ants 2 - Camponotus Postoculatus Forel

Until I started doing macro / close-up photography, I never realized how many species of ants there are and rarely even noticed them (unless they got into my sugar bowl. LOL!!) One day I watched this fight between these two ants. It went on for about 20 minutes and eventually the one was so exhausted, it just let itself be dominated by the other. I am not sure what the fight was about , if it is two males, or a male and female.