General Mills' Chocolate Cheerios say "All Natural Ingredients" on the box, however, the ingredients list "Artificial Flavour" as one of the ingredients. When I asked General Mills about this they said the cereals Artificial Ingredients are proprietary and secret.
Cheerios contain a number of ingredients that are NOT good for you including chalk, and cement cleaner. In 2010, General Mills decided to use genetically modified ingredients "regardless of the longterm health affects to humans."
Please do not feed Cheerios to your children.