Dill said that his mother and stepfather were not interested in him.
One night Scout goes into her room to find what she thinks is a snake under her bed. It turns out to be Dill. He has run away from home. When she asks him why, he tells her that his mother remarried, and is more interested in his new stepfather than in him.
"[He]- they just wasn't interested in me."
This was the weirdest reason for flight I had ever heard. "How come?"
"Well, they stayed gone all the time, and when they were home, even, they'd get off in a room by themselves." (Ch. 14)
It turns out that his new stepfather promised to spend time with him, but never did. His mother spends time with her new husband and is ignoring him, so he went back to Maycomb and snuck into Scout’s room.
Dill has not had much luck when it comes to parents. When he was younger, he used to lie about his father. First he said he didn’t have one, but that he wasn’t dead, which confused Scout. Then he made up stories about him.
[He] had seen his father. Dill's father was taller than ours, he had a black beard (pointed), and was president of the L & N Railroad.
"In a pig's ear you did, Dill. Hush," said Jem. (Ch. 4)
Dill’s situation with his father provides a sharp contrast to Scout and Jem’s situation with theirs. While Atticus may not be the perfect father, since he is old and half-blind, and somewhat unorthodox, he is heads-and-shoulders above Dill’s fathers.
Atticus is present in many ways, despite the long hours he works. He listens to his children, gives them advice, and provides moral guidance. He also gives them other ways to be proud of him, because he courageously stands up for what he believes in. Oh, and he is a dead shot!