The mockingbird serves as both the real and symbolic representation of joy and innocence in To Kill a Mockingbird. The bird itself is the living personification of love and sweetness, placed on the earth to entertain their human counterparts--to "sing their hearts out for us." The mockingbird isn't capable of doing harm to man; they "don't nest in corncribs" or "eat up people's gardens." The bird is also witness to some of the story's most important events: Awaiting the culmination of Atticus's stand against the mad dog, "the mockingbirds were silent." Scout is reminded of this scene as she awaits the jury's verdict, how
... the courtroom was exactly the same as a cold February morning, when the mockingbirds were still... (Chapter 21)
In both cases, the mockingbirds remain silent out of respect for the innocent victims: the rabid dog, Tim Johnson, has to be put down even though he is a random victim of the disease. Tom Robinson is one of the story's human mockingbirds, an innocent man who has been thrust into a potentially deadly situation through no fault of his own. Also symbolic of the mockingbird is Boo, whose lost innocence begins after his father's unjust punishment. Accusations fly about Boo, but few are ever substantiated. As Jem and Scout head along the dreary path toward the school on Halloween, they think of Boo as they pass the Radley house. Suddenly, possibly as a warning to the children,
... a solitary mocker poured out his repertoire in blissful unawareness of whose tree he sat in... (Chapter 28)
It is Scout who likens Boo to the mockingbird in the final chapters. To preserve Boo's privacy and innocence, she agrees with Sheriff Tate's decision to call Bob Ewell's death self-inflicted. Charging Boo with Bob's death after he has saved Jem's and Scout's lives reminds her that
"... it'd be sort of like shootin' a mockingbird, wouldn't it?" (Chapter 30)
Most of the children in the story are also human mockingbirds. Jem and Scout suffer a loss of innocence through their observations and participation in the events of the story. They lose faith in the judicial system when Tom is wrongly convicted; Scout sees first-hand the hypocritical nature of the "devout" women of the missionary circle as well as the poor teaching skills of her teachers; and the children's lives are put in danger when Bob Ewell decides that the only way to get even with Atticus is to kill Jem and Scout. As for Dill, his family life is an unhappy one, and the only time he is really contented is when he is shuttled off to Maycomb to spend the summers with his Aunt Rachel. Dill experiences more love and happiness with the Finch family than he ever receives at home in Meridian, and his observations of the trial make his physically sick.