Too bad for Wart: he has to stay in bed for the next three days (by order of his governess).
Wart demands that Merlyn change him into something while he's stuck in bed. Only Merlyn can't cast spells through the keyhole (he can only talk to Wart this way to avoid the wraith of the governess).
An ant is what Wart wants to be turned into this time, since he's been occupying himself by watching the ant farm Merlyn has placed in his room.
Merlyn warns Wart that ants are belligerent (but Wart doesn't know what that means). Although Merlyn thinks it's too early for this phase of the boy's education, he gives in anyway.
When Wart is transformed, he finds himself in the ant colony, greeted by this sign: EVERYTHING NOT FORBIDDEN IS COMPULSORY.
He thinks this is ominous. Just a bit.
Wart hears voices in his head, along with music, both of which come in through his antennae.
Ant-Wart (apparently named 210021/WD) watches another ant move around some dead ants. It appears he doesn't quite know what to do, but is compelled to be moving the bodies around anyway. There's no thought behind this, which really ticks off Wart.
He discovers there aren't even words in ant-language to express certain concepts: happiness, freedom, right, or wrong.
When Wart tells the cadaver-moving ant that he (Ant-Wart) is "doing nothing," the ant reports him as being insane (or, in ant-language, Not-Done).
After a conversation with another ant via the wireless broadcast, Ant-Wart tells them that he fell on his head and can't remember anything. He is promptly told to go join the mash squad again—whatever that is.
It turns out that the mash squad is responsible for partially digesting food that will then be deposited in a sort of storeroom for later use. Wart is grossed out by this.
During their work, the mash squad chats to each other, and Wart soon discovers there is an "A" nest and a "B" nest. The ants are happy to be part of the A nest, and would hate to be Bs.
One frequent topic of conversation is that of executions. The conversations are all the same, actually, with only the ant's registration numbers changing. Boring!
Ant-Wart sees the Leader—a female ant whose only job is to lay eggs, boss people around, and order executions.
Oh, about that storeroom that the partially digested food would be deposited into? Well, there's not one. Anytime an ant needs food, they stop one of the mash squad (like Ant-Wart) and feed directly from him. Double gross!
But worse than that was the discovery that Wart eventually makes after living as an ant for a time: that asking questions is forbidden—is actually regarded as a sign of insanity.
Soon, ants from Nest B start to invade, and are promptly killed by the As.
And then all-out war commences, with the ant-broadcasts focused on patriotic messages, and lectures about how Nest A must kill all of those from Nest B if they do not want to starve to death or be slaughtered themselves.
Luckily, Merlyn rescues Wart from this soulless existence just as the war is about to start in earnest.