Two male Chinstrap penguins like these formed a real-life romantic attachment which led to a children's book, says The New York Times.

It seems like a children's book about penguins hatching a baby at the Central Park Zoo in New York would be a cute story for parents to read to their kids.

"And Tango Makes Three" is such a story, with one twist, the adult penguins are both male.

The book, written by Justin Richardson and Peter Parnell, has once again topped the American Library Association list of the 10 most frequently challenged books.

According to a news release from the ALA: "A challenge is defined as a formal, written complaint filed with a library or school requesting that a book or other material be restricted or removed because of its content or appropriateness."...