I have a curious 6 year old, who's started asking a lot of questions about exactly how babies are made. So I've been looking for age-appropriate books. Turns out it's a bloody minefield. I'm sure it won't surprise any of you to discover that it's possible to buy children's books about making babies that don't mention men or women at all. Just, you know, that "some people" have sperm and "some people" have eggs. And people are buying these books and reading them to their children 
SUCH COMPLETE AND UTTER INSANITY!