Why did the hens confess to Napoleon in 1984?

Everything seems to be going wrong with the Animalist revolution, and the absenthas
been made the scapegoat for all the problems that beset the farm. Buthas got in into his head
that Snowball must've had accomplices in his dastardly plot to destroy the revolution. So he
accuses a number of pigs of being in secret contact with Snowball and demands that they confess
their crimes. The charges are...