my gut instinct is that much like what I get up to in bed, zero is not natural ... buuuut we have a maths priestess in our midst so hang on a minute while I peek at her answer... um, depends who you ask - yeah, that's it
In nature, there's no zero of something. You can say there are zero pandas at your home, but that thinking is more complex than the rationale behind natural numbers because it involves an hypothetical situation.