I've wanted to read "The Secret of NiMH" since I watched the Don Bluth animated feature back in 1985.
When I lived in Jamaica for a couple of years with relatives, the film had captured most of my schoolmates' imagination as well as their parents' pocketbooks - at the time, a graphic novel based on the animation sold like hot cakes on the island. When I borrowed a classmate's, I was a little disappointed by the illustrations, even noting that characters were often disproportionate to their portrayal on film.
Mind you, 8-year-old me didn't think this, it just seemed off, but then age and experience made me realize what I just told you.
I feel blessed that often, many of the animated features I watched as a child, I later read the book.
For example, "The Last Unicorn", "Watership Down", "The Return of the King", and "The Hobbit".
Right now, in my 30s, I made it a point to read "The Secret of NiMH" which is actually "Mrs. Frisby and the Rats of NiMH" (the original title!).
And get this: Author Robert C. O' Brien, who wrote the original book, his daughter, Author Jane Leslie Conly, ended up creating two books based on the first!
So I ended up reading her "Racso and the Rats of NiMH" and "R.T., Margaret and the Rats of NiMH" before reading the original story!
This story helped to perceive animal stories as true literature, and not simply as 'kiddie fiction', though there is nothing wrong with that as long as the story is written with the best of intentions.