Most rain forests date back some two to three hundred million years.
This extreme age has allowed many unusual and complex relationships to develop among the inhabitants of these tropical ecosystems. In the rain forest of the Cameroon in West Central Africa lives a floor dwelling ant known as Megaloponera foetens, or more commonly, the stink ant. On occasion one of these ants, while looking for food is infected by inhaling a microscopic spore from a fungus of the genus Tomentella. After being inhaled, the spore seats in the ant's tiny brain and begins to grow, causing changes in the ant's patterns of behavior. Driven on by the growth of the fungus, the ant embarks on a long and exhaustive climb.