Harpaphe haydeniana (the yellow-spotted millipede, almond-scented millipede or cyanide millipede) is a species of polydesmidan ("flat-backed") millipede found in the moist forests along the Pacific coast of North America, from Southeast Alaska to California. The dark coloration with contrasting yellow-tipped keels warn of its ability to exude toxic hydrogen cyanide as a defense. Despite the various common names given the species, the coloration pattern, cyanide