Millipedes do not bite or sting, but many species produce foul-smelling and irritating liquids to ward off predators. A number of millipede species, like the desert millipede, secrete or spray toxic liquids that are harmful to other insects and small animals. A mixture of hydrocyanic acid, iodine, and quinone, the toxic liquid can cause blisters on human skin similar to chemical burns. Blisters usually look like brown or purplish lesions, which last for a few days before peeling. In some cases, lesions may take an extended amount of time to heal. If the toxin gets in a human’s eyes, it can cause severe irritation of the eyelids and cornea and, in very rare cases, result in blindness. Though irritating to the skin, the liquid cannot cause death or serious illness, and millipedes are not considered poisonous. However, individuals may want to avoid picking up or directly handling the occasional pests.