If it concerns you, go the person who started it and communicate. Work it out between the two of you. This is a way to encourage the kids to talk to each other rather than grumbling. Don't hold a grudge. Don't put it off.
Homework is important, get it done every day.
Usually it is not much. Hurry and go home and do it. No fighting, no hitting, and no weapons at school. It goes on from there. This is to remind them to keep anything harmful out of their bodies.