Animal Farm
Why is there a fight in the farmhouse?
.
.
The pigs and humans begin to play poker, and a fight erupts when Napoleon and Pilkington both put down the Ace of Spades at the same time..... obviously, someone is cheating. As the animals witness the pigs and humans quarreling over their poker game, they cannot distinguish between them.
http://www.gradesaver.com/animal-farm/study-guide/summary-chapter-x