Why is 'animal farm' a fable?

"fa·ble" –noun

1. a short tale to teach a moral lesson, often with animals or inanimate objects as characters; apologue: the fable of the tortoise and the hare; Aesop's fables.

(Dictionary.com)

Animal Farm (1945) is a satirical novella (which can also be understood as a modern fable or allegory) by George Orwell, ostensibly about a group of animals who oust the humans from the farm on which they live. They run the farm themselves, only to have it degenerate into a brutal tyranny of its own. A fable is a story that teaches a lesson using often animals as characters. In Animal Farm, The animals portray the early communist government in Russia after World War 2. It shows the problems with communist government styles, as the animals turn on eachother and tension escalate. It recreates the problematic development of the Soviet Union.

A fable is a story where the characters are talking animals.

I think because of the talking animals. Plus is there a moral or a lesson?

Because it has animals in it. It also tells a story with a pretty pointed message in it.