In March we replaced 10 feet of our sewer. It was so full of roots and dirt, I have no idea how it was ever draining at all! My children both understood what was going on. Benjamin explained in detail. "Mommy, do you know why the toilet is not working? The tree trunks are growing down into the broken pipes."
Stuart said "Daddy! Ring Ring" (which is the phone, in case you missed that.) "Man!" "Man!" What man, Stuart? "Toilet! Man! Man! Toilet!" It was expensive but satisfying, since the old pipes were so bad.