Why aren’t dads in children’s books?

I have not given this much thought, but the idea behind this article is that dads are way under-represented in kids’ fiction, save for the famous
Hop on Pop. Let me know what you think – we’ll even do a contest. Name kids’ books with dads who are at least present in the story and extra points if they are positive literary forces.   

Where are all the nice, normal dads in children’s books?
Fathers in children’s books are rarely positive figures. But as dads do more childcare, it’s time publishers took note

[From Where are all the nice, normal dads in children’s books? – Times Online ]

Contest details to come…