How does Squealer show appeal to fear in Animal Farm by George Orwell?

Appeal to fear is a technique propagandists use to make people forget about the truth and instead get so scared that they believe what the person is saying. Squealer is Napoleon’s propagandist. That means he is charge of getting the animals so confused that they do not know what to believe, so they believe him. He gives speeches to the animals to explain what Napoleon is doing and try to convince the animals to go along with Napoleon's plans.

Appeal to fear is one of Squealer’s favorite techniques. He tells the animals that Jones will come back if they do not go along with Napoleon. He distracts the animals from what is really happening. A good example of this is when the other animals discover the pigs are consuming the milk and apples. By way of explanation, Squealer says,

"It is for your sake that we drink that milk and eat those apples. Do you know what would happen if we pigs failed in our duty? Jones would come back! Yes, Jones would come back! Surely, comrades," cried Squealer almost pleadingly, skipping from side to side and whisking his tail, "surely there is no one among you who wants to see Jones come back?" (Chapter 3) 

Apparently, the animals find Squealer's words and his skipping from side to side and whisking his tail very persuasive. His body language is also a distraction. Squealer knows it is persuasive, because it makes him seem innocent. His comments about Jones are pure hogswallop, though. The pigs are just trying to explain away the fact that they are taking over the humans’ role in the farm and taking all the luxuries for themselves. Squealer convinced the animals the pigs can eat all of the milk and apples because otherwise Jones will come back.

Later, after they run Snowball off the farm, Squealer again uses the appeal to fear tactic to convince the animals that Snowball is in league with Frederick so the animals will not miss Snowball (one of the initial leaders of the farm). 

"Comrades!" cried Squealer, making little nervous skips, "a most terrible thing has been discovered. Snowball has sold himself to Frederick of Pinchfield Farm, who is even now plotting to attack us and take our farm away from us! Snowball is to act as his guide when the attack begins” (Chapter 7).

No one will question Snowball's departure once they have been told he was in league with the humans the entire time. This is another appeal to fear. Squealer tells the animals Snowball has betrayed them. The animals believe this because they believe everything Squealer says.