Humanity (and therefore the animals in this allegory) has a need for justice. We seek retribution for sins or ills committed against us. Take a look at a typical criminal investigation. The investigation is finished when a suspect is convicted and sentenced... even if the suspect was innocent and inaccurately found guilty.
Napoleon uses the scape-goat, a style of propaganda which points blame elsewhere. Some of the problems on Animal Farm were within Napoleon's power to solve, others were not. No matter what the problem was Napoleon pointed to Snowball so the animals would point their need for justice there. Had there been opportunity for them to place their anger, they would have lashed out on Snowball.
There are two reasons, in my opinion, that Napoleon blames everything on Snowball.
First of all, it is important that Napoleon himself should not be blamed for anything. There are problems on the farm, and so it is helpful to blame them on Snowball. If animals started blaming Napoleon for things, he might lose his position of power. So he has to blame Snowball to make it look like he himself is perfect.
The other thing is that it helps him keep power by making the other animals afraid. If they think that Snowball is out there trying to ruin their farm, they will rely more strongly on Napoleon to keep Snowball away, to defend them from Snowball.
So both ways, the main idea is to keep Napoleon in power.
He blames everything on snowball as a scapegoat. He knows that if the animals no that it was him who was mucking things up on the farm that he would not be able to be the leader.
because he think that everyone will follow the rules of snowball and not him.
hope it helps. :)
I agree with the teachers above. Napoleon is based off of Stalin and like Stalin he would do anything to keep power. He blames Snowball because he wants to make himself look good and so he can't be blamed for any setbacks on the Windmill Construction and the injuries/deaths of some of the animals. When things went bad and people started questioning Stalin due to Leon Trotsky, Stalin's Snowball, Stalin first exiled Trotsky to Siberia and then when Trotsky ran away to The New World publishing stories that badmouthed Joseph Stalin, he sent an assassin to shut Leon(Snowball) up for good. By constantly blaming others for his failures and setbacks, Napoleon tries to make himself into a god.