The live action part of the film shows what I believe to be actual
Japanese Waltzing Mice. The literature describes them as white with
black markings and their behavior also seems to match published
descriptions.
The cartoon version of one of the mice says "Nature intended me to spin
and I'm gonna leave well enough alone."
The cartoon tells the story about what is either a scientist or a
wizard (He wears a very Harry Potter hat). This guy transforms "ugly"
animals into "beautiful" ones. Lizards into doves, for example. Then
some new ingredient is accidentally added to the mix and it turns a
cage of spinning mice into devils who make a new potion and turn the
man into a giant rabbit.
The doves (that used to be lizards) save the day and make a new potion
that turns the man and mice back to ther original states. The man tears
up his book, singing:
So the lesson is that you can't/shouldn't improve on nature. Funny, it was
"The knowledge in that book of mine
Is better left unknown
And as for this my motto is
Leave well enough alone."
the "improved" lizard/doves that saved the day. And nobody bothered
to change them back into lizards.