Chorus: Why do you cry out thus, unless at some vision of horror
Cassandra: The house reeks of death and dripping blood.
Chorus: How so? 'Tis but the odour of the altar sacrifice.
Cassandra: The stench is like a breath from the tomb.
These lines, a quote from Aeschylus's Agamemnon, constitute the opening of Watership Down. If ever an author wished to give a better signal to the audience that this book was not a children's book, it would be hard to imagine how. And just in case you were left in any doubt, the next three chapters begin with quotes from Henry Vaughan's The World, Xenophon's The Anabasis and Shakespeare's Hamlet.
Now, by 'not a children's book' I do not mean that children cannot enjoy it. Of course they can: children can enjoy many books aimed at adults. I myself read it at aged eight and have read it many times since, as both a child and an adult. But a children's book is a book that is specifically aimed at children, in terms of one or more of vocabulary, content, tone or theme. The Silver Sword, for example, though addressing the serious themes of the German and Soviet occupation of Poland, is told through the eyes of children and in a tone and manner that makes the grim realities of war and occupation accessible to a child's eyes.
There is none of this in Watership Down. As indicated by the source and content of the chapter headings, a quick glance at any page will show clearly that the language and sentence structure is written in a way an adult would find natural to read, with no 'toning down' for a younger audience. The culture, lives and depth of the rabbits' world are explored thoroughly and the attention to detail (including footnotes) in ensuring the details of rabbit live are (as far as possible) true to nature is consistent throughout. There are page-long digressions on the nature of moonlight.
Crucially, as well, the rabbits around whom the story centres are not children, but adult rabbits. They have adult (rabbit) concerns: the survival of the warren, mating, finding food. And the trials and tribulations they face are told bluntly, without flinching from the detail: whether it is the destruction of the Sandleford Warren, Big Wig in the snare or the oppression of Efrafra, Adams does not flinch from the detail. We have descriptions of rabbits tearing each other to pieces underground as they fight to escape from poison gas.
There was a time when many people, especially those who preferred more literary genres, assumed that fantasy was automatically for children. My English teacher at school was one of those. They were puzzled as to why The Lord of the Rings wasn't filed in the children's section of the bookshop, or why any adult would choose to read a book with elves in it.
The recent fame of A Game of Thrones has done a lot to change this. The combination of George R. R. Martin's relentless showcasing of adult themes with the TV show's popularity has forced even the most ardent sceptic to concede that not all fantasy is aimed at children - and with this, a broader recognition that whether or not a book is a children's book depends on its content, tone and style, not on whether it mentions dragons or magic. And of course, a book does not have to be explicit to not be a children's book.
Unfortunately, it seems that talking animals have not escaped that trap. Because when it comes down to it, there is really nothing about Watership Down that would make one think it was a children's book at all, except for that fact that it contains talking animals. But this is a superficial point; just like whether or not a book is fantasy, it tells you nothing. Redwall and Narnia are children's books; Watership Down and The Lord of the Rings are not.
Some covers recognise this more than others. My own version shows a black silhouette of a rabbit at sunset with grass in the front, a picture which appears in many ways somewhat sinister. Other versions go with cute frolicking rabbits - and then wonder why people are surprised to find that they're not reading Peter Rabbit. The film, marketed at children, naturally ran into similar difficulties.
If you've not read it, I'd strongly recommend it - at any age from about 8 upwards It's a book which people of all ages can enjoy. But just remember: it's not a children's book.1
I’m aware the Adams believed he had written a children’s book. However, he was wrong.
"Unfortunately, it seems that talking animals have not escaped that trap."
Where does Animal Farm fit into this?
I have occasionally seen anecdotes about people calling that a children's book, but only posted by others mocking those people's literary ignorance; I haven't seen anyone make the argument themselves that it's a children's book.
Does Animal Farm avoid the trap because it's allegory/satire?
Is Watership Down allegorical at all, or just straightforwardly about rabbits? (I read it once a very long time ago and wouldn't have noticed if it was allegorical or not.)