Getting A Wiggle Worm to Sit Still and Listen

Two of my boys (6,7) do NOT like to sit and listen for any length of time.  They do ok for a little while (think 10 min) but pretty soon they are very antsy.  While begin very antsy, they of course are not listening because all they are thinking about is how much longer it will be until they can get up and what they are going to do when they can.  We do a lot of reading in our house.  I needed to figure out a way the boys would be able to sit, keep themselves busy and still be able to listen to me.  So, they draw while I am reading.  They get their colored pencils and notebook out when we sit down to start reading and start drawing.  This keeps their hands busy and keeps everyone quiet, but they are still listening to me as I am reading.  How do I know?  At the end if what I am reading (history, science, Bible, read aloud) I will ask them to narrate back to me or ask questions about what I just read.  i think allowing them to draw while I read actually clears their minds of thinking about how long it will be until I am done and what they will be able to do then and allows them to focus on what I am saying.  They also do not interrupt and ask how much longer and I don't get frustrated because they keep interrupting!  It's a win, win situation for all of us!