How do the animals in Animal Farm react to major's song? (Key verb must start with u)

In the first chapter of George Orwell's Animal Farm, Old Major (who symbolizes Karl Marx and, to a lesser extent, Vladimir Lenin) spends his final days exhorting the animals on Manor Farm to rebel against the humans who have oppressed them (specifically, the farmer Mr. Jones) and obtain a "perfect comradeship" with their fellow animals.

Old Major also teaches the animals an anthem for the coming revolution: "Beasts of England." This song depicts the utopia which will supposedly occur after the animals rebel against the humans. Old Major's song unites the animals (much as the "Internationale" served as the rallying anthem for the Communist revolution in Russia). Old Major soon dies, but the unification which "Beasts of England" inspired enables the animals to revolt against Jones and the oppression of Manor Farm. Unfortunately, as the animals would later learn, oppression can come from other animals, too.