Animal Farm

Why are the animals happy in their work, despite the fact that they work like slaves? What is ironic about their reason for being happy?

They think that their doing it because they choose to, instead of someone forcing them. It gives them a sense of control and freedom in a way.

Its ironic because they aren't truly choosing to do it, nor do they have the freedom or control they think they have, the pigs can enforce rules and whatnot upon them and they are completely powerless against it