In Animal Farm, compare earlier times on the farm to the later ones.
I think that the first chapter is probably going to be where a great deal of focus lies in this question. The opening chapter resides largely with Old Major's vision of a world without humans. There is a solidarity present in the chapter, as well as a belief that the clear enemy would be the humans who consume without producing. The feeling that comes out of the first chapter both to the animals and the reader is a fairly clear one in the identification of the humans as the source of the animals' problems. As this progresses, and as power becomes a central issue for the animals, these clear feelings become increasingly muddled. For example, in chapter 7, when Clover does not know what to think in seeing her fellow animals slaughtered, it is a reflection of the state of affairs surrounding all animals on the farm. She is still fairly convinced that life is better without the humans, but at what cost, in terms of seeing the death of so many animals in such a brutal manner. It is this confusion that is in such stark contrast to the first chapter and the initial feelings of revolution present.