How can we get kids at middle school to behave better?

My daughter's middle school is a cess pool. The teachers are overwhelmed. Lunchtime there is awful. We were trying to brainstorm on how we could make it better. We would really love some practical ideas that we could apply or pursue. As a parent, I'd really like to able to support teachers who seem forced to spend more time on behavior than teaching. Is it possible to achieve such a change in this day and age? Thank you for your thoughts.