Why does napoleon convict four pigs of treason and kill them?

Napoleon convicts the four pigs of treason in George Orwell's "Animal Farm" after they are accused of conspiring with Snowball, whom Napoleon views as a traitor. This act serves to eliminate any dissent and consolidate his power by instilling fear among the other animals. The public execution of the pigs is a display of his authority and a warning against rebellion, reinforcing his tyrannical control over the farm. Ultimately, it symbolizes the corrupting influence of power and the betrayal of the revolutionary ideals.