pea?
 

think the leaf looks like a pea of some sort

It's called Mimosa pudica (sensitive plant)
 

I had ! of these a long time ago and it died, their a very interesting plant and kids think their great the way the close, here's a link to a video on youtube about all the different names it has ;-)
http://www.youtube.com/watch?v=BLTcVNyOhUc