Hamming around- hamming up

Here is the sentence: it’s just in a mood of playfulness; people are hamming around. There’s an expression, “hamming around”, “hamming it up".

Could you give more explaination about these two expressions: hamming around and hamming up. Thanks

A ham is an actor who performs with very obvious emotions and expressions. “Hamming” is alot like exaggerating or overreacting to something. When people “ham around,” or “ham it up,” they draw attention to themselves. They fool around by acting silly in photos or overdramatic about something.

Here are some links to photo of kids “hamming around/hamming it up”.
http://webclipart.about.com/library/apeople/blkid13.htm
http://bp3.blogger.com/_tP5srC-RjO0/SHWm-BQU9sI/AAAAAAAAAkY/Lso6BexuBf8/s1600-h/IMG_8196[1]

Hope that helps!

For sure that helps. Thanks Allison.