Ebbie
In your last paragraph is exactly what I experienced when I was up in the Yukon. They make a very eerie screeching sound. Whistling would make them respond back and they would also dance (or go up and down as well as left to right)to the whistling. Now I'm sure this is not true, but it sure did in fact happen.
Yes, good thread.
Here is also a great thread to view each day.                  
http://antwrp.gsfc.nasa.gov/apod/astropix.html

You can also go into the archives ans see some great pictures of the northern lights.
Beer