Bird Identification: CLOSED: What kind of birds (and what were they doing??), 1 by TNTulip

TNTulip wrote:
A couple weeks ago (in Nashville, TN), we suddenly had about 20 of these birds fly into our backyard and land in one of our large trees. They only hung out in the tree for about 30 minutes and then they all flew off together. Another big group of the same kind of birds came through and landed in the same tree about 10 minutes later, stayed for about 30 minutes and then they flew off together.

While the birds were in the tree, it looked like they were turning upside down while they were sitting on the branch! Their feet stayed in the same spot on the branch, they just flipped foward for about a second and then sat up straight on the branch. They ALL did this!! It was really strange to see! They would fly in, land on a branch, flip upside down on the branch, and flip right back up. We couldn't figure out what they were doing???

We would love to know what kind of birds these were. They were really cool looking. Anyone know?