Tropical rainforests are the world's oldest ecosystems.
Records show that the forests in some regions have existed in more or less their present form for over 70 million years. High temperatures coupled with abundant rainfall produce the steamy atmosphere that is common to rainforests from Australia to the Amazon. So much, in fact, that animals living in the treetops never have to touch the ground. A vast number of these species live in the high protection of the treetops prospering in the shade, food, and shelter provided by the rainforest. The canopy, or upper layer of the tropical rainforest, is one of the last places on earth to be explored and it is where many species of plants and animals remain undiscovered.