There was a rabbit outside my office window. It was eating grass, but it was also watching me as I was watching it. Because it was still, and I was close enough to see it clearly, I was able to focus on its ears.
Of course animals with big ears are more attuned to sound, but to watch the mechanics was fascinating. Both ears up and facing forward. Aimed the same direction as its eyes. There’s a sound on the right. The right ear rotates right. Sound on the left. Left ear rotates left. Both rotate back to the front.