The eggs of the crab louse are laid usually on the coarse hairs of the genital and perianal regions of the human body. Crab lice may also be found on other areas of the body that have coarse and relatively sparse coverings of hair, such as the beard, moustache, eyelashes, underneath the arms.
Quotes within quotes. When a run-in quotation contains quotation marks within the quoted material itself, use single quotation marks in their place. When the material being quoted contains a quotation within a quotation (i.e., something in single quotation marks), use double quotation marks.
He is quoting within a quote and using the correct marks, double for the person talking and single for what she is quoting. But the speaker gets to the end of her sentence at the same time she gets to the end of the internal quote. The author used 3 quotation marks at the end of the sentence.