Old Major wishes to speak to the animals after Jones retires for the night because what he has to say is an indictment of the rule of human beings. Old Major wants Jones to be asleep so that he can speak to the abuses of animals at the hands of men. Old Major waits until Jones goes to bed in order to freely express his thoughts that both deconstruct the present system on the farm and articulate a vision of the future. The deconstruction lies in Old Major's beliefs that the animals are exploited by the human beings. He argues that the animals are used and abused, useful only to humans in so far as they help to generate profit. When the animals have outlasted their usefulness, Old Major argues that they will be slaughtered. In addition to this, Old Major speaks of a vision whereby the animals are able to assert control of their own destiny. He renders a vision to the animals in something called "Animalism" whereby humans are the enemies and all of the animals work together as one common entity. Old Major has to wait unti Jones slumbers in order to speak of both visions as they represent a direct attack on Jones as a manager. In doing so, Old Major sets the wheels in motion for both revolution and the themes of Orwell's work.
Old Major wanted to inform them about how miserable and difficult their lives were and persuade them to consider the idea of rebelling and running the farm themselves through an idea called "Animalism". In Old Major's vision, all animals would be treated equally and come together to make the farm a better place to live for the animals.