What superstitions do the children have in connection with the Radly house?

From the text:

"Boo was about six-and-a-half feet tall, judging from his tracks; he dined on raw squirrels and any cats he could catch, that's why his hands were bloodstained -- if you ate an animal raw, you could never wash the blood off. There was a long jagged scar that ran across his face; what teeth he had were yelow  and rotten his eyes popped, and he drooled most of the time."