Orwell wrote both Animal Farm and 1984 as satires on society, with a focus on corruption of power and the adoption of collectivism. When there is a single overriding power in charge of everything, there is no outlet for individuals to seek their own goals and ideals; suppression of the individual creates an environment that promotes collective thinking, and thus societal stagnation. One example in 1984 is the Two Minutes of Hate, where all citizens are compelled to feel irrational, emotional hatred of a "common enemy." Because the citizens cannot create their own opinions, they have no reason to question Big Brother.
In Animal Farm, a similar focus is placed on propaganda techniques. The sheep, who are incapable of independent thought, are entirely informed by emotional arguments without deeper meaning.
...Napoleon was better at canvassing support for himself in between times. He was especially successful with the sheep... It was noticed that they were especially liable to break into 'Four legs good, two legs bad' at crucial moments in Snowball's speeches.
(Orwell, Animal Farm, msxnet.org)
This removal of individualism is key in the construction of an almost-religious dictator figure. Instead of a government based on the good of the people and the defense of equality and liberty, both governments are based entirely in control of the citizens and exploitation of their abilities.
the pigs control the animals in animal farm. everything is done as the former wish. they are like dictating the other animals what to do and what not to. similarly in 1984, big brother is always watching all and the thought police can read your thoughts thus the name. they will control your thoughts and emotions and make sure you don't rise as a rebellion. both show politics in its true essence.