Or this can apply to any non-primate, non-dolphin animal, I suppose.
One of my cats loves to hop onto my bathroom counter in the morning when I’m putting my contacts in. He walks all around the (small) countertop, which often causes him to have to look in the mirror. What I find strange is that he never, ever, stops or even pauses at his reflection. From my human-perspective, I can see two things going through his brain:
Hey, that’s a cat there
Hey, that’s me there
Both of these, at least once I would think, would require him to pause and look a little more closely. Even when he comes across my other cat, as well-known as they are to each other, there is always a small pause, a flicking of the ears, a focusing of the eyes and assessing the situation before moving on. So, I have to rule out #1 above, and think that he does “recognize” himself. But it’s almost as if his brain makes his reflection invisible - he never ever seems to look at himself (he does see and recognize me in the mirror).
The mirror used to freak out my cats. I believe they thought it was some strange cat that has no smell and was stalking them. (as they stalked it) It was pretty funny to watch the kittens charge the mirror and then sudden run away from the cat charging them.
Now they seem to have figured out that it’s not a real cat and they don’t pay it any mind.
If you have a medicine cabinet at a 90 degree angle to the mirror, try opening it at an angle that produces a hundred reflections of your face. Used to freak the hell out of my cat.
None of our cats seem to have any interest in the mirror.
On the other hand, Misty seems to have a fascination for looking at her reflexion in windows, glass doors, picture frames, etc. Perhaps because it’s less clear than the mirror, so she can’t quite make out what it is. But then Misty has never been the brightest crayon in the box, so to speak. (She’s not stupid, but she’s a little off).
The very first time Muffin saw herself in the mirror in our bedroom (when she was a 12 week old kitten), she arched her back and danced the entire way along it, as tears of laughter streamed down my face. Now she pays absolutely zero attention to the cat in the mirror. I often wonder what she thinks it is.
A dog I used to own would jump on my bed, see the dog in the mirror, heckles would go up and he’d start barking, then he’d dive off the bed and run around to the room on the other side of that wall - he was convinced it was a window and that he was seeing a dog in the next room. Puzzled me that he was smart enough to understand the concept of “window”, but not smart enough to ever figure out that the other dog would vanish without a trace before he got there. He never gave up trying to catch the dog in the next room.
