Animal Farm uses anthropomorphism to give the animals human qualities.
In this fairy tale, when the humans go to bed the animals come out and run the show.
Word had gone round during the day that old Major … had had a strange dream on the previous night and wished to communicate it to the other animals. It had been agreed that they should all meet in the big barn as soon as Mr. Jones was safely out of the way. (ch 1)
The animals are practically human. As the book progresses, there is great deal of anthropomorphism, or the description of animals as if they were humans. Obviously the animals can speak English. They can hold paint brushes, use ladders, and even read. Most importantly, they seem to be able to talk. The animals can obviously talk to the humans too.
[There] were constant rumours that Napoleon was about to enter into a definite business agreement either with Mr. Pilkington of Foxwood or with Mr. Frederick of Pinchfield | but never, it was noticed, with both simultaneously. (ch 6)
Not only do the animals act like humans, they interact with them on an equal level. At first, they take advantage of them by paying with fake money. Soon enough they realize that doing business with the animals benefits them. Soon they are working together, and there is little difference between them.
The animals act like humans because they are acting out an allegory of the Russian Revolution. They are also following the process that many human revolutions go through. The old government is overthrown with promises of paradise, and then the new government because just as abusive.