What I want to know is how they ever get the chocolate on them and why does it taste so good?
I can see the misunderstanding Kraz, you see "chocolate mousse" is a form of creamy dessert typically made from egg and cream (classically no cream, only egg yolks, egg whites, sugar, and the chocolate or other flavorings). The egg whites are beaten before being incorporated into the other ingredients to produce a light and fluffy yet extremely rich confection. It is then chilled to maintain its aeration.
So you see, you are confusing "moose", the largest extant species in the deer family, with "mousse" named for it's light airiness, much like the hair product of the same name.
It's a common faux pas.
...
Ok, I took the joke way too far.
...and P.S. I used Wikipedia a lot!