Deep in the steamy jungles of Borneo, in Malaysia, is a massive crack in the limestone outcrop that leads to an intricate system of caves. Entering the caves is not for the squeamish. In the dank interiors are millions of bats that hang from the roof, while the floor and walls are covered with cockroaches, beetles, rats and other creepy bugs that feast on bat shit and dead swiftlets that fall out of their nests. The caves also house snakes that feed themselves on the rats and cockroaches. The air smells thick with ammonia because of the bird droppings. The guano deposit on the floor is estimated to be 10 feet deep. Wooden walkways through the explore-able section of the caves keep visitors safely above the horrific creatures that litter the ground.

Photo credit: Col Ford and Natasha de Vere/Flickr