Symbolism, Imagery, Allegory
Ah, life. Isn't it wonderful? The emmet (an old-fashioned term for an ant) sure thinks so. It has a life of routine. It does what it's programmed to do without any questions. But does it bring happiness? Beckett did say in Waiting for Godot that "habit is a great deadener" (1.85). And yet, the emmet persists. It gets on with its task and provides for the colony. Its existence is life in a microcosm. We go to school (and/or work) so that we can become productive members of society. Which makes us, in a way, kind of like the emmet.
The emmet's appearance also points to the hierarchy within the natural world. Think: big fish eats medium fish, which then eats smaller finish, ad infinitum. It's a fact of life that is easily forgotten when you're at the top of the food chain, like us humans. Winnie's worry on whether she combed her hair or not—an act she doesn't have to do—is ludicrous when compared to the poor emmet, who's carrying an egg twice its body weight. Perhaps the emmet functions as a reminder for Winnie to keep it real, to remember the big picture in life.