Why did Bob Ewell attack Scout and Jem? How were they left so vulnerable to bing attacked. Why dis Atticus misread so badly the signs that Bob Wwell might try to hurt him or his family?

Bob Ewell attacks the children to get revenge against their father. He has the opportunity to do so because the children are walking home in the evening, and they are by themselves..... something that would not have been considered out of the ordinary at the time. Atticus misread Ewell's signals because he did not believe him to be a physical threat to himself or his family..... Atticus believed that he was merely reacting to embarrassment.