Fish
The opening line of the story situates the Herdman as the worst kids in the world. This explicit assertion is given a little nuance through the comparative power of the simile. “The Herdmans moved from grade to grade through the Woodrow Wilson School like those South American fish that strip your bones clean in three minutes flat.” This metaphor refers to the piranha. The piranha is a species with a reputation for converging together to attack a single large victim. The narrator is suggesting with this metaphor that the Herdman kids individual are bad, but working together as a collective makes them even worse.
Pregnancy
An essential aspect of the story is that the Herdman kids are introduced to the story of Christmas for the very first time and without all the attendant baggage of sermons and Sunday School lessons. The metaphorical language used to pretty up the cold hard facts of the nativity. When the narrator’s mother and pageant director begins reading the story to the Herdman kids and gets to the metaphor of Joseph and Mary, one of the Herdman kids brings it down to its literal meaning: The fact that the Herdmans haven’t had their introduction to stories of the Bible shaped and formulated through the filter of a minister or Sunday School teacher allows their perspective to be one that immediately strips away the varnish to reveal the foundational truth.
Refugees
The most important use of metaphorical imagery is the moment that the narrator reaches the epiphany toward which the narrative has been relentlessly moving the whole time. “They looked like the people you see on the six o’clock news—refugees, sent to wait in some strange ugly place, with all their boxes and sacks around them.” The reference is directed the two Herdman kids that are playing Joseph and Mary. Not only are they novices in the world of Christianity, but they are also newbies to the world of stagecraft. Their entrance onto the stage is somewhat less than smoothly rehearsed and the more realistic and affecting for it.
