M is for Masochism

As the mother of 4 children, I am asked the following question:  "Why?"  I know, that surprises some of you, but people do ask me why I have 4 children, and if they are truly brave, cringe as they ask the follow-up, "Will you have more?" 
There is just one answer to both questions:  I am a masochist.  It is the reason I became a mother in the first place.  Why else would I purposely decide to go through at least 10 years of short hair and write "Not Tissue"  on the lower half of all my pants?
I have joined a preschool group.  Or more accurately, I have volunteered to help teach 5 smiling terrors once a month, with a 3 week reprieve between torture sessions.  Now, those of you who have not fallen off your chairs laughing at this are probably wondering what the big deal is.  Well, it's pretty simple: I am not a teacher.  I am an excellent enforcer, as my children will all tell you, but I am still learning how to teach.  Except for the whole slow neck roll with lots of cracking noises, I could probably teach that, but once again, that's because I am an enforcer. 
Monday was my first teaching experience.  We did F is for Fire Fighter.  I was going with F is for Fish or Frog at first, but couldn't find enough stuff for younger children.  The boys came over at 10, and were slated to leave at 11:30.  I was trying to not get too nervous and convince myself it would be like educational babysitting, and that it would go by in a flash.
At 11:45, all the boys were out the door, and it was safe for me to curl up in a ball and cry.  In a different room than Ben of course, because he had a great time.  We played Smoke, Smoke, Fire (Duck, Duck, Goose), read books about fire fighters and fire safety, and watched a video about a fire fighter and his equipment. At the end, the boys got fire fighter badges and free time to just play.
Sounds like a pretty normal, somewhat educational preschool experience, right?  Now remember that there are FIVE of them, and they are all BOYS.  I also had a little screamer named Caleb who wanted to be held the entire time.  I had to hide the trains, keep attention focused, make sure no one cried (too hard, anyway), and  keep them all in a similar condition to when they arrived.  That is EXHAUSTING work!  I don't know how teachers do it!
So, in two weeks I am in charge of the letter H.  Any ideas? Or ways to keep my sanity that don't involve chairs and duct tape?