Snowball and Napoleon are sending pigeons to neighbouring farms and beyond, to tell the animals about the rebellion. News of the rebellion has spread to the surrounding county. The farmers at first pretend not to be troubled about the rebellion, believing that the animals cannot possibly make a success of the farm. But as time passes the farmers become more and more troubled, and their animals become more and more emboldened. The tune of Beasts of England is now known by nearly every animal in the county. The farmers try to spread lies about torture and slavery on Animal Farm, but the animals of the county do not believe them. They whistle the tune and sing the words of Beasts of England, though they risk terrible beatings by doing so. More and more stories are heard of individual animals disobeying and in some cases attacking their human masters.
One day in October, Jones, all his men, and half a dozen others from the neighbouring farms, attack Animal Farm. They walk up the laneway through the main gate. They are all armed with sticks except for Jones, who carries a gun. The animals, however, are well prepared. After an initial skirmish where the pigeons and geese attack the humans, Snowball attacks them, supported by Benjamin, Muriel and all the sheep. The men repulse this attack with their sticks, and Snowball sounds the retreat. They fall back to the farmyard, pursued by the men, who think that they have triumphed. However, they have walked into a trap.
As soon as the men are in the farmyard, a number of the larger animals emerge from the shed behind them, and cut off their retreat. Snowball’s group now attacks again. Snowball charges at Jones. Jones fires a shot at Snowball and wounds him, but this is not enough to prevent Snowball from crashing into him and sending him tumbling to the ground, the gun flying out of his hand in the process, Now Boxer joins the attack, rearing up on his hind legs and striking viciously with his hoofed forelegs. Boxer strikes one of the men on the skull, apparently killing him. At the sight of this, the other men run for their lives, back down the laneway and out the gate. The invasion is over.
In the post-battle excitement, Boxer is extremely remorseful for killing the man, while the animals suddenly realise that Mollie is missing. They search the farm, and find her hiding in a corner. She fled the battle as soon as the gun went off. They return to the farmyard to find that the man was only stunned, and has since recovered and escaped.
The animals celebrate their victory. The flag is raised, Beasts of England is sung. A medal for “Animal Hero, First Class” is created and awarded to Snowball. A medal for “Animal Hero, Second Class” is created, and awarded to a sheep that died when Jones fired his gun. They decide to keep the gun and place it at the bottom of the flagstaff, to be fired each year on the anniversaries of the rebellion, and of the battle.