Lightless Troglofauna. This species of giant beetle lives only underground, in the deepest caves where light does not shine. Their carapace is a dull white color, and they tend to reach over 4 feet in length over their thin body. They communicate via pheromones and by vibrating their thorax against the rock beneath them, which, due to their sensitive tympanal organs, they are able to hear through many hundreds of feet of stone.