In case you’re still amused to read this, let me explain my confusion.
1) From your first reply above, I gathered you consider it valid to call animals atheists.
2) From your first reply to me, I gathered you consider it technically valid to also call rocks atheists, but somewhat misusing the term (as it’s not what it ”is meant to describe”), like calling rocks blind.
3) Those two premises lead me to ask my question, to pinpoint where the difference between the two in your view stems from: why isn’t calling animals atheists equally wrong.
4) In your answer, I felt you said the two claims (”animals are atheists”, ”rocks are atheists/blind”) are equally valid, which obviously goes against my assumption in 2) and thus broke my chain of reasoning about yours.
From your comments in the other thread below, I see you write atheism ”is the simply the absence of the position that they do exist”. If I’m (finally) reading you correctly and put it another way, you don’t preclude a question (in the most abstract sense) of their position being posable for someone/-thing to be considered atheist; this would suggest that my mistake was at 2), assuming you consider ”rocks being atheist” somewhat less correct than ”animals being atheist”, when in reality you consider them just as valid: an object (in your view) does not have to be able to be theist to be rightly called atheist.
As I said, I have no strong inclination about this myself, but writing this I do seem to see at the back of my mind a tendency to presuppose at least a potential for theism for a creature/object being validly considered an atheist. It doesn’t mean they’ve been posed the question of supernatural beings, just that they have the potential to develop such ideas. This would obviously exclude rocks, as they lack even the remotest potential of developing any ideas at all (and equally, calling them blind would be wrong in the sense that they will never have any potential of seeing).
On the other hand, intelligent, adult animals (such as dolphins) might very well fall into this category of potential theists, and thus be correctly called atheist in this system. Not because they have developed theist views and then rejected them, but just because they have the potential to do so, and haven’t. Very small children (human babies, as well as non-human non-adult animals) would not, because they lack the required capability for the potential to emerge. (Obviously I have no evidence of either intelligent animals’ capability to develop ideas of supernatural, nor of babies’ lack thereof; these are just based on my gut feeling.)