What quotes demonstrate that Bob Ewell is a bad parent?

The reader is introduced to one of Bob Ewell's children, Burris, in chapter three on Scout's first day of school. He is not bathed, has lice, and he speaks very disrespectfully to his teacher. This shows that the boy is not being taken care of properly at home, nor is he being taught to respect others. When Scout asks her father about the Ewells, he tells her that they have been a disgrace for many generations and that they are so backwards that it is difficult to force them to obey many minor laws--such as going to school and hunting out of season. Scout says that Bob shouldn't hunt out of season and Atticus replies as follows:

". . . it's certainly bad, but when a man spends his relief checks on green whiskey his children have a way of crying from hunger pains. I don't know of any landowner around here who begrudges those children any game their father can hit. . . but he'll never change his ways" (31).

This passage shows that Bob Ewell is so selfish that he would rather spend his money on alcohol rather than feed his children.

In chapter 18, Atticus cross-examines Mayella Ewell and asks her if she loves her father. She doesn't say yes. In fact, she says, "Love him, whatcha mean?" as if the words "love" and "father" don't mix. She ends up answering that he is "tollable, 'cept when--" Atticus prompts her to finish her sentence but she simply says, "Except when nothin'. . . I said he does tollable" (183).

What she's hiding is that her father gets drunk a lot and beats her. Atticus even proves in chapter 17 that Bob Ewell is left-handed and Mayella was beaten on the right side of her body--suggesting that Bob did beat his daughter at least once. This isn't good parenting, either. It's abusive.

Also in chapter 17, Bob Ewell is asked if he ran for a doctor for Mayella after she had been raped, but his answer is as follows:

"The witness said he never thought of it, he had never called a doctor to any of his'n in his life, and if he had it would have cost him five dollars" (175).

 If Bob Ewell has never called for a doctor for his children during his whole life, how would any child be able to survive under his guardianship? The kids must be lucky enough not to get hurt or sick! Mayella does shed more light on the subject because during her testimony she says the following:

". . . he sometimes went off in the swamp for days and came home sick. . . it was everybody for himself as far as keeping clean went: if you wanted to wash you hauled your own water; the younger children had perpetual colds and suffered from chronic ground itch" (183).

With no mother around to help these children, much of the responsibilities of the household fall onto Mayella's shoulders. Bob Ewell isn't a good parent because he doesn't provide love, daily food, clothing, education, or medical help to his children; and, he isn't sober or around enough to make a difference anyway.