Troglobites are cave-dwelling species, such as the blind salamander and Belizean white crab that evolved in isolated underground worlds. Celebrate 20 years of Planet Earth. Head over to the webpage to find out more: https://www.bbcearth.com/shows/planet-earth Subscribe: http://bit.ly/BBCEarthSub Sign up to our newsletter for the latest news, updates and exclusives from BBC Earth https://www.bbcearth.com/newsletter #PlanetEarth #DavidAttenborough #PE20 Watch more: Best of BBC Earth 🌍 https://bit.ly/BestOfBBCEarth Best Animal Fights 🥊 https://bit.ly/BestAnimalFights Videos over 10 minutes ⏰ https://bit.ly/3SHJCEJ Planet Earth III 🌍 https://bit.ly/PlanetEarthIIIPlaylist Frozen Planet II ❄️ https:/bit.ly/FrozenPlanetIIPlaylist Blue Planet II in 4K 🌊 https://bit.ly/BluePlanetII4kPlaylist Welcome to BBC EARTH! The world is an amazing place full of stories, beauty and natural wonder. Here you'll find 50 years worth of entertaining and thought-provoking natural history content. Dramatic, rare, and exclusive, nature doesn't get more exciting than this. This is a commercial page from BBC Studios. Service information and feedback: http://bbcworldwide.com/vod-feedback--contact-details.aspx