"Devour" Commercial

The M&M's commercials are always some of my favorites.  They take inanimate candies and give them life, and the commercials are always funny and enjoyable to watch.  There is an art to their commercials too.  They really use precise and detailed animations to create the M&M characters.  They have very specific personalities through the details they are given.  

But the animators do something great.  They insert these characters into real life footage.  I'm sure that the process is difficult.  My guess on how they do something like this is that they take a similar approach to what we have been learning in class with the "inserting ourselves into a movie" project.  There must be a way to simply take the animation and place it into the footage.  I doubt a green screen is used, but maybe it is for some parts.

Here is a commercial that I'm talking about...