system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] Can animals tell he isn’t quite human?
gpt
Can animals smell the difference between a Kryptonian under a yellow sun and a normal human being. 

I would say yes. 

He would smell different because he isn't producing metabolised byproducts (waste/sweat) based on breaking down food. 

  So they would recognize he is different but that wouldn't necessarily mean anything negative.  

He exhibits the same emotional based physiological cues as a normal human (Smiling, laughing, fear, anger, seriousness) so an Animal would visually recognize him as being like everyone else, he would just smell different. the fact that he would carry the lingering scents of other humans might mark him as close enough to not cause a negative outcome.

In fact its possible some animals might respond more favorable to Superman because he doesn't ever smell/appear afraid in their presence.