Eight is enough

Today I kept a total of the children not belonging to me attending Prestwich time.  And  Tada!  It's eight.  That's right folks eight kids.  Some made it inside despite my protests.  Others did not.  Either way, the yard was so full of popped water balloons that I refused to let even my own children come inside until it was cleaned.  Here's a little story problem for you to solve:

The Prestwich family has a total of four children.  Eight children decide to come over and play.  After a fun filled day of balloon popping and toy scattering, Mom yells at everyone to clean it up. If all the children run home, how many are left to deal with the mess**?

I'm thinkin' tomorrow sounds like a good day to shoot stuff*,***
( the vultures and coyotes can clean up that mess).

We are leaving for an extended camping trip tomorrow.  Mommy needs a time out.

 *I'm kidding of course.
 **Most children cleaned up something, at least.
 ***Also, we are not going to shoot anyone with our (sort of) harmless airsoft guns.