Your argument that because an animal looks into a mirror and sees another animal it is not self aware is fallacious - SOME animals may do this but as not all animals of the same kind do do this, it cannot be argued that this proves those animals who do are not aware they exist. I have six cats, including two born in my home, and not one has ever looked into a mirror and seen another animal; all six ignore their own reflection.
You are very confident you are right, Surreylass, but I would ask you to provide both druiaghtagh and myself with proof that there is an actual difference between sentience and self-awareness. In other words, is there any sentient being who is not also aware that they exist?
NB I accept your definition of sentient in your last post but just wonder if you can prove that something with a 'developed nervous system and brain' can also be unaware that they exist.