why did the animals feel a "vague of uneasiness" (chapter 6)

The other animals are “conscious of a vague uneasiness” because the Seven Commandments forbid trade with humans and the use of money. Napoleon assures the animals that they, at least, will not have to make contact with human beings. He has already set up an agreement with a solicitor in town named Mr. Whymper, who will act as their intermediary to the human world.