No Children Please? On wedding Invitations?

I'm looking for a nice and proper way to say "Leave your kids at home!" on a wedding invitation. We all know that the poor kids really don't want to be there, they get bored, try to entertain themselves and then become a disturbance during the ceremony. Then of course the reception is fun, for about 20 minutes before the little tykes get tired and cranky, Let's face it, weddings aren't really a kid friendly event. So, what's a good polite wat of letting people know that they need to leave junior at home, without causing drama with cousin Gertrude who will insist that little Suzy would be an angel (Suzy wont be an angel, she a normal kid)?