Now retired, I am moving to the country and want to raise a few [12-15] chickens. I want to free range them during the day enclosed by an electric movable fence, around about 20x70 foot area for a future garden. Instead of netting the top, I was wondering if some compact discs [CDs] strung on heavy fishing line across the width every 6 feet would deter hawks. I think about 3 on every line would spin or wobble in the wind and the flash may keep them from diving into my hens. Any comments?