When taking a roiling horde of children to get passports done, be sure to take some kind of calming medication. Valium might work. Or large quantities of wine.
For you, or for the kids. It really doesn't matter much. Either they will be quiet and good for the ten hours you wait in line, or you won't care how they're behaving.
I wish someone had told me that before we had to go to the Post Office for our passport applications this morning. One way or another, it would have kept my blood pressure within acceptable levels.
Also - the Post Office won't let you use their bathroom. I'll throw that tidbit in for free.