UFO Armada In Between Port Aranasas and Austin

Over on UFO-Watch.com, a person has posted about a pretty amazing sighting they experienced while driving from Port Aransas to Austin. They even stopped to check it out and were a witness to a gigantic flock of metallic orbs that kept rotating around in different positions, and even disappeared at times, for 20 minutes. Question is - did this person see a flock of birds, or something stranger? Here's the full encounter:

I live in Texas and i was driving back from Port Aransas Texas to Austin Texas on Sunday April 12. As i was driving on a long stretch of country road i glimpse up at the sky and see about 200-300 little dots in the sky very close to airplane height. I pulled over my car and watched it for about 20 minutes. I couldn’t see the objects at first with my bare eyes, so i put on my shades and could see each one in prefect detail. these objects were sphere shaped and from what i could see they had a metallic color to them like the color of mercury. These objects also had a dark shaped bottom. They were moving in crazy rotations and turns that no bird or airplane could do. They would all separate and then join back in rotation in a clockwise and counterclockwise movement. What also cought my attention was that these objects would vanished as they turned in whatever direction, and reapered as they turned back to their original position. There were two flocks of about 200-300 UFO’s and they seemed to be doing the same thing and moving closer to each other. I figured hell with it and as i was getting into my car i saw the two flocks of spheres join together to form an armada. I saw what i saw and for a fact i know that nothing on this planet has the technology to make movements like that. I also know that these objects were not ballons of birds of any kind. As birds do not fly in flocks of 300 for no reason, this isent even migration season. Tell me what you think cause this is beyond anything i have ever seen.