Squealer gives regular speeches to the animals, on Napoleon's behalf, to convince them that Napoleon and the other pigs are working hard for all of the animals. Squealer tells the lower animals that the work carried out by Napoleon and the pigs is "of a kind that the other animals [are] too ignorant to understand." In this way, Napoleon, through Squealer, tries to convince the animals that they are dependent upon the pigs for the efficient running of the farm.
Squealer also regularly tells the animals, on Napoleon's behalf, that their lives are much better now under the leadership of Napoleon than they ever were before. This is demonstrably untrue, but Squealer produces "lists of figures" which, as far as the working animals can tell, "invariably demonstrate that everything [is] getting better and better."
Napoleon also manipulates the animals by having them believe, through Squealer, that it is him, Napoleon, who protects them against the evil Mr. Jones. When, for example, Napoleon bans the Sunday meetings, he has Squealer justify the ban simply by asking the lower animals, "Surely, comrades, you do not want Jones back?" Napoleon and Squealer justify many of their decisions in this way—they simply have the animals believe that all decisions are to protect them, in some way they are incapable of understanding, against the return of Mr. Jones.
The most detailed speech that we hear (albeit indirectly) from Napoleon is at the end of the novel, when he explains to the humans how he has manipulated the animals into working harder than ever before. He boasts that he has banned the animals calling one another "comrade," this being, he says, a "foolish custom." Napoleon also boasts that the hoof and horn have been removed from the farm's flag. The hoof and horn symbolize the lower, working animals on the farm, and Napoleon getting rid of these symbols reflects how he has disenfranchised and silenced these animals.