Perseverance
A common theme from Nicodemus's point of view is perseverance. When he and the other rats get trapped by the scientists that are looking to genetically modify them, Nicodemus never gives up hope and is always trying to find freedom. The book always portrays him as constantly trying to get out of the cage and getting out into the open world. This is the advantage of being a rat, since rats have been through such hard times in society and have learned to cope with these kinds of hard situations.
Stereotypes in Society
This can be clearly distinguished in the book between the mice and rats. The rats are the bottom of the food chain. The rats are known to be vile creatures that steal from other animals to make a living and a life. Rats are commonly associated in the book with a pest such as fleas. Mice, on the other hand, are more civilized and less inclined to involve themselves in dangerous situations. They are always hiding from predators but successfully make a living and are content in their home lives.
