COLORADO, USA — A "mega den" of rattlesnakes in Colorado is becoming active after the winter.Thanks to a livestream that launched Monday, scientists studying the den on a craggy hillside in Colorado are learning more about these enigmatic — and often misunderstood — reptiles.The public can also watch on the Project RattleCam website. The project is a collaboration between California Polytechnic State University in San Luis Obispo, snake removal company Central Coast Snake Services and Dickinson College in Carlisle, Pennsylvania.As the camera launched Monday, snake researchers said it is still a bit cold at the den, so you can expect...