But the voice of the buffalo was the voice of Amanda Beale, and its teeth were her fingers pulling and wrenching his poor ear till he was sitting upright. (46.5)
Notice that its not Mrs. Beale or Mr. Beale who calls Maniac home to their family. It's Amanda, who is Maniac's friend first. It's Maniac's peers (Amanda gets a timely assist from Mars/Snickers here) who have the ability to get Maniac to do things. In other words—friends, not parents.