The National Park Service has taken to Facebook to warn its visitors against licking the "potent toxin" secreted by some of its toads. "Here is the “ribbiting” late-night content no one asked for," the hilarious post detailing the dangers of the psychoactive Colorado River toad.It continued to say: "As we say with most things you come across in a national park, whether it be a banana slug, unfamiliar mushroom, or a large toad with glowing eyes in the dead of night, please refrain from licking."