If lizards and rodents are active where you are hiking, rock climbing or fishing, beware of the Western rattlesnake, says Paul Gorenzel, a wildlife and fisheries biology researcher at UC Davis. From sea level to nearly 11,000 feet, the snakes are common throughout California's rural terrain. The best protection for humans is using common sense in choosing protective leg and footwear when traveling in snake country, says Gorenzel. If a rattlesnake has just been beheaded, it can still bare its fangs if you reach down to pick up its head. The heat sensory pits in the head will still be functioning, and the warmth of your hand will activate the striking reflex. Though the head cannot strike, it can still bite and inflict venom, notes Gorenzel.