Beneath our feet lies a hidden world where life survives without sunlight, warmth or oxygen. This episode explores the underground ecosystems shaped by bats, cave insects, crustaceans and the mysterious olm — a blind amphibian that can live for over eighty years and survive years-long fasts. From deep caves in France to sealed caverns in Romania, the film reveals species adapted to extreme conditions and the mineral landscapes that shelter them. Documentary: Secret Life Underground EP:2 Hidden In The Depths Directed by: Vincent Amouroux Production: Transparence productions We fully own the rights to the use of the published content. Any illegal reproduction of this content will result in immediate legal action. #documentary #animalintelligence #animals #fulldocumentary #freedocumentary #life #bats #deeplife #ecosystem #darkness #insects #insectsfacts