Symbolism, Imagery, Allegory
We don't want to hate on our rodent buddies—Remy of Ratatouille fame is both adorable and talented—but rats are bad news in All Quiet on the Western Front.
Just when you think it can't get more difficult for a man to survive a day in the trenches on account of the guns, bombs, rotten food, lack of water, and claustrophobia, the rats show up.
There's something disturbing about how brazen and aggressive these rodents are. They become a different kind of enemy to the soldiers and wage a different kind of war on them. Paul and his friends are being attacked from all directions – bullets fly at them from the Front and rats gnaw on them in the trenches. There is no safety.
They seem to represent the ugly side of nature, the side that would eat a dog, a cat, or a man if need be. Before they arrive, we have a good feeling about Mother Earth and all she does to protect and provide for the soldiers. But when the ratatouilles show up, we realize that things have really taken a turn for the worse—it's as though Mother Nature is turning on mankind.
There's no safety, no peace, no quiet when rats are around. They crawl on the soldiers' faces in search of their food, and they eat the dead bodies.