Hawks?

Around 6:00 today there was a very strange formation of hawks above McKinney in Stonebridge Ranch. I noticed them when I was getting in my car. There must have been thousands of them, extremely high up in the sky. The trail seemed to strech for miles. I got a video camera to tape this and will post it asap. It is very hard to see the birds, but if you look hard enough you will see them swirling in the sky. It is Friday the 13th.