I think my take is that for a being to be considered atheist it can only be after said being has (or has the potential to) given consideration to the notion that god/s exist. Hence kittens, hamsters and worms are not contenders, imo. (And as for rocks, ie all matter, ie the universe, is just plain silly).
I don't think I agree with that.
I can imagine an isolated tribe of humans who live in harmony with nature which for some reason never developed, or came into contact with, theistic beliefs or god concepts. So if you would tell them about gods or such beliefs, they'ld have no idea what you are talking about.
I'ld call those humans atheists. Simply because they lack any beliefs to qualify as theists.
So the way I see it, atheism is a default position.
You need to actually do something, believe / make specific claims, in order to qualify as a theist.
You don't need to do anything at all to qualify as an atheist.
You are an atheist
by default.
You require
additional, specific beliefs / actions to qualify as a theist.
The strict definition of "atheist" is "without personal god beliefs".
So anyone without such beliefs, is an atheist by definition.
We are all "a-globdycok-ists". Eventhough nobody claims globdycoks exists or even know what they are.
We all lack believe in such anyway.
Because nobody does, we have no use for a word like "a-globdycok-ist". But that doesn't change the fact we all lack positive, affirmative beliefs in globdycoks..