The forest floor is perhaps the most inhospitable place of all -- dark, damp, and full of potentially dangerous wildlife. And nowhere is more forbidding than the original heart of darkness, the Congo. This is an undercover world of subterfuge, secrecy, and camouflage. Nothing is what it appears: venomous snakes look like leaf litter and invisible flies carry fatal diseases.
Host Charlotte Uhlenbroek reveals the problems of surviving in this difficult place for the chimps and gorillas that live there. They need nests to keep themselves off the forest floor at night, and they need to know what's edible and what's poisonous.
Photo credit: Corinne.Staley/Flickr/Creative Commons License