I thought I"d pass on this experience I had with the younger volunteer ushers.
I once had a couple of young girls show up for ushering over an hour early. They had claimed to be 16, and I never asked for any proof. I told them that they could either come inside the theater and hang out there or come back later for their shift. They opted for coming back later.
Well, they came back too late for their shift, and I told them I couldn't use them, as walk-in was over. They begged me to let them stay until the show was over because they 1. lied about their ages, and 2. were hanging out all over town and 3. They were being picked up after the show by their parents, and would be in trouble if they weren't at the theater.
Another time, I had a few young ushers who were star struck and that was their only reason to be at the theater. They were running up and down the aisles to each other to scream about seeing someone famous and tried to get autographs while ushering.
I know-not all teenagers are like that, but after a few similar incidents, I stuck to using the adults.
<-----I'M TOTES ROLLING MY EYES