The Question and Answer section for Animal Farm is a great resource to ask questions, find answers, and discuss the novel.
Animal farm is not a republic: it is a dictatorship. Napoleon took power and, like all dictators, purged anyone who might challenge his authority. Napoleon rules through fear and intimidation.
When they meet to receive their orders for the week, the animals no longer sit all together. Rather, the dogs and other pigs gather around Napoleon, Squealer, and another pig named Minimus. They are now the "inner party". They are the animals with...
From the text:
The pigs now revealed that during the past three months they had taught themselves to read and write from an old spelling book which had belonged to Mr. Jones's children and which had been thrown on the rubbish heap.