I don't see how mixing up a blank screen more often with one dot than with multiple dots indicates they think of "none" as a number. The more things there are t

I don't see how mixing up a blank screen more often with one dot than with multiple dots indicates they think of "none" as a number. The more things there are the easier it is to detect at least one, so it seems completely plausible that something with a concept of "none" but without a concept of "zero" would also mix up no items with one more often than it would with two or three. Hopefully the original research addressed this, but it felt like the Quanta article was reporting the results in a way completely disconnected with the material it had just introduced. If we know the animals arrange quantities like a number line, why is there no report on where the animals place an empty set in that experiment? If we know that some young children don't understand the empty set can be a number, then why aren't results from young children on these tasks compared? There are some interesting results described, but I wasn't convinced at all by the argument about zero specifically, which they make a big deal of in the intro and discussion. To be honest I think Quanta is a bit overrated on HN in general, but that's another issue.