Sentence:  "Foxes have holes,' Uncle Abner," said Daisy, " 'and the birds of the air have nests, but the son of man hath not where to lay his head.' Why should we worry when we have such a bully place as this tent?" "Ish ka <WSD>bibble</WSD>," said the Reverend Frank. "Well," said I, "about the time the mosquitoes begin to come out of the marsh, you'll begin to <WSD>bibble</WSD>." 
Meaning of the word marked with <WSD> tags:  To worry.