I'd like to propose an alternative to what you said, because under certain circumstances the 'upright' thing and 'talking to one another' isn't necessary. Allow me to explain...



Imagine a being which walks on all fours, and can only communicate telepathically, but can understand Human language (Namely English) very well. The being is also sentient and intelligent on a 'human level'.



Please elaborate why if you disagree with me.