I am just sharing this, I have noticed and wondered why my tetras are still sparring and chasing each other around especially the two biggest ones. I had them for 7 weeks now and thought they had established the pecking order of their school. Was watching them when I saw that they are clearly divided into two groups surrounding the two biggest tetras. They are evenly divided. Its fun to watch though it looks like a mini turf war. They school together when I place my hand or do something inside the tank.