As someone who appears old enough to have grandchildren, I tend to smile and say "Sorta like herding cats, isn't it?" when I see a woman with two or three young ones in a store.

When the kids are obviously above 7-8 years of age and being little hellions, I am not so mellow.  A Parent is responsible for turning toddlers into semi-adults.  Along the way, the concept of discipline needs to be understood and used.

Otherwise, when they are 18 year old 'adults' they will still be acting like those two year old toddlers.