So, I was thinking about how some animals eat and shit through the same hole. Like they eat, digest the food, and then "puke" the shit.
Then I imagine what if there is a sentient species of aliens that were like that. We would consider them super gross.
But then I realize that we inhale and exhale through the same hole. Our waste gases exit our bodies thorugh the same hole we use to breathe in. It is also the same hole that has our chemical receptor organs.
There are animals on Earth that aren't like that. Fish take water with oxygen through their mouths and expell water with CO2 through their gills.
What if most aliens in the galaxy were like that and consider us super gross for exhaling through our mouths?