Note: I have mentioned the ability of various non-human animals to count and assess quantity in previous articles in my “Reason” series, but this article goes so much farther than my brief reflections.
In animals numbers are sort of hardwired (analog), same goes for "zero" as in empty. They do not seem to have ability to do arithmetic as a symbolic operation, their arithmetic is analog (if at all). One could argue that humans pre-numbering had similar problem. You need to invent symbols/numbers to do numerical (which is really symbol manipulation) math.
In animals numbers are sort of hardwired (analog), same goes for "zero" as in empty. They do not seem to have ability to do arithmetic as a symbolic operation, their arithmetic is analog (if at all). One could argue that humans pre-numbering had similar problem. You need to invent symbols/numbers to do numerical (which is really symbol manipulation) math.