In Animal Farm, what do the pigs do that shocks the other animals?
As Napoleon's reign continues, he makes subtle alterations to the commandments. When things go wrong, Napoleon begins to blame everything on Snowball. Napoleon uses propaganda in these ways to convince and/or brainwash the animals into following his lead. When Napoleon tells the animals that Snowball had been allied with Jones from the start, the animals are shocked at the news:
"I do not believe that," he said. "Snowball fought bravely at the Battle of the Cowshed. I saw him myself. Did we not give him 'Animal Hero, First Class,' immediately afterwards?"
But Napoleon also uses fear and violence to reinforce his position of authority. One of the most shocking acts that he commits is in Chapter 7. The animals are faced with a grain shortage. Napoleon has Squealer declare that the hens must give up their eggs in order to pay for the grain. The hens are outraged:
They were just getting their clutches ready for the spring sitting, and they protested that to take the eggs away now was murder. For the first time since the expulsion of Jones, there was something resembling a rebellion.
Napoleon orders the hens rations to be stopped. Later in the chapter, the hens, a number of other animals, and four pigs are slaughtered by the dogs for their insubordination. Some admitted to being influenced by Snowball in some way. These confessions were likely coerced. After the executions are over, the animals contemplate the shock of Snowball's (alleged) treason and the violence they've just witnessed:
When it was all over, the remaining animals, except for the pigs and dogs, crept away in a body. They were shaken and miserable. They did not know which was more shocking - the treachery of the animals who had leagued themselves with Snowball, or the cruel retribution they had just witnessed.