The creatures in the movie "The Descent" are referred to as Crawlers). They are humanoid creatures that live underground and have adapted to life in the dark. They are blind but can detect prey via sounds and echolocation). The Crawlers are stealthy and ruthless hunters that torment a group of women for the majority of the film. They amplify the movie from a simple drama to a downright scary horror film. The Crawlers are depicted as cavemen who never left the caves and evolved in the dark. Their anatomy closely resembles humans, which would explain why they are listed as human subspecies with males, females, and children within the colony during the time they spent living in the caves. It is unclear what their motivation in stalking the women is, aside from simple bloodlust.