No, but they sure taste fantastic. Just ask the other children at the Chef's recital who grabbed them all before the Chef could go for seconds -- he didn't mind too much, maybe because we left half of them at home. We often take his own treats to avoid any allergy problems, and it was his idea this time to share with the others.
Recipe (if not on box):
Stick of butter
Bag of marshmallows
Enough cereal to make firm bars, but not too firm.
Melt butter and marshmallows in microwave for about 3 minutes, add cereal, pour into pan and put in fridge to set.