The louse shares with us the misfortune of being prey to the typhus virus. If lice can dread, the nightmare of their lives is the fear of some day inhabiting an infected rat or human being. For the host may survive; but the ill-starred louse that sticks his haustellum through an infected skin, and imbibes the loathsome virus with his nourishment, is doomed beyond succor. In eight days he sickens, in ten days he is in extremis, on the eleventh or twelfth day his tiny body turns red with blood extravasated from his bowel, and he gives up his little ghost. Man is too prone to look upon all nature through egocentric eyes. To the louse, we are the dreaded emissaries of death.
-- Hans Zinsser, Rats, Lice, and History (Boston: Atlantic Monthly Press, 1934), 168.