These are Mexican Free-Tailed Bats that I photographed Saturday night in Texas. They are about the size of a field mouse, but they fly surprisingly fast. They were really tricky to focus on in the dark. I almost never shoot photos with artificial external lighting, but for these light bats, I used an old off-camera strobe to momentarily light them up. They are really amazing little creatures. I’m surprised that they fly as well as they do.