Today was the polar opposite of yesterday’s high school lunch.
7 high school kids instead of 60, and it was Zen.
And my theory proved true (at least for today). We had less transactions, more $$$ sales.
2, 3, and 4-top tables of adults with a higher average ticket, and a much calmer atmosphere to dine in.
Even taking the delivery sales out of the equation (two large amounts), we still had more dollar volume and less people served.
I had some really great suggestions on my previous two posts; allowing only a certain number of HS students in at one time, the other to draft a “Dear HS Student” letter which I could leave on the front counter for them to read while waiting for their drink.
I’m going to wait it out a bit, see what transpires.
(former) Pizza Professional with OCD 
I have been following this and am glad it’s slowing down and perhaps working out. No doubt with school starting the kids were all happy to see each other, etc. and now they are getting back into the groove – and have less money!
One comment I wanted to make is that you have every right to say/write what the expectations are in your restaurant. Right now, they are behaving this way because ‘they can’. Most kids would not behave this way at home and should not behave this way in public. They need to clean up after themselves, not use the restaurant as a hangout, and conduct themselves like the young adults we expect them to be (but mine aren’t teens yet so what do I know!)… You could also designate a H.S. only dining area – like the back patio… your adult guests would probably appreciate it anyway!
I also agree with you that they can bring sack lunch from home, if they purchase drinks, but can not bring in food from other restaurants. This is an opportunity for them to learn proper etiquette as well. And, it’s good for them to hear these things from other adults other than their parents – reinforce the message.
Good luck!