Have you ever lost a key on a field trip ?
I'm a new driver and I take quite a few field trips. Losing a key during a trip is one of my worst fears. I leave the key in the glove box because I feel it's safer there than taking it with me. It's not attached to anything besides a tag with the bus number, so it's small.
We haven't went over what we do in that situation, but it's common sense to call dispatch. That'll suck when it's late at night and one of them has to leave home to deal with it. If it happened to you, what happened after ? And how far were you from base ?