Two words that instill both loathing and joy in a mother's heart.
Whenever one of my children say they've been playing with the Legos or Playdoh, or that they want to, I loath the end results. The cleanup can be a pain. Fortunately for me, my children are pretty good about putting their toys away when asked to.
Joy is another reaction, because I know that they will be occupied for a long time, mostly quietly.
And, as I heard somewhere-- Silence is golden, duct tape is silver. (I don't know who said this, so I'm sorry--can't credit you!)