Subject: Why does microwave-cooked popcorn have an electric charge?

I cook popcorn in my 700W microwave using a hard plastic contain 
designed for this.  After dumping out the popped popcorn there 
are usually tiny fragments of the popped kernels left inside the 
container.  If I put my hand OUTSIDE the container near such a 
fragment, it moves away as if repelled by a static electic 
charge.  What's truely wierd is if I put my hand INSIDE the 
container near a kernel (not touching anything) I see no such 
repulsion (nor an attraction).  What's going on, why does the 
placement of my hand make a difference?

Re: Why does microwave-cooked popcorn have an electric charge?