In George Orwell's novella Animal Farm, the animals have negative feelings about the social order in which they find themselves victimized; they are treated unfairly in life by human beings, and they don't like it.
Once the animals have run off the farmer, Mr. Jones, and established self-governance, they begin to feel hopeful. They find initial happiness in expressing their new government's central tenet—that all animals are equal.
Soon, however, two pigs named Napoleon and Snowball begin to campaign to be the new leader of the farm. Napoleon, being the more ambitious and power-hungry of the two, takes control via underhanded means and begins to abuse the other animals as much as Mr. Jones had done previously. The animals soon realize they have fallen into the same unfair social order from which they had initially sought to escape.