In what ways are the Ewell children feral?

The Ewell children in To Kill a Mockingbird are feral because they live in filth and are unruly and uneducated.
The Ewell children are mostly taken care of by the oldest child, Mayella. Her father is a drunk who beats her and the other children. The property they live on is in a constant state of dirty, cluttered disrepair. Scout says that the Ewells go to the dump and bring things home, then leave those items—from old shoes to a discarded dentist's chair—on their property.
She says that people in town aren't sure how many Ewell children there are, indicating that some people say six and others nine. Scout says, "There were always several dirty-faced ones at the windows when anyone passed by." At the trial, she says that the children are often sick and some of them have something called ground-itch.
Scout is in class with Burris Ewell. On the first day, Miss Caroline tries to send him home to wash his hair after "a cootie" falls out of it. Scout describes him, thinking, "He was the filthiest human I had ever seen. His neck was dark gray, the backs of his hands were rusty, and his fingernails were black deep into the quick." When he leaves, he says he won't be back. He says he only comes to the first day of school every year, which is apparently what most of the Ewell children do.