There is an article in the BBC, Virgin births discovered in wild snakes, that makes me wonder if virgin births in snakes was the inspiration for imagined, religiously-associated “virgin births” in people. After all, snakes were considered divine long before gods conceived in human form. It may have been part of why snakes were considered special.
While this article suggests that this is a new discovery for humans, more than likely, pre-historic peoples were familiar with this phenomenon. I expect that contemporaries in “non-developed”, snake-worshipping societies would also be familiar with this.
Sophia Waits 