A kingdom of several million species, more than animals and vertebrates combined, fungi are hidden from us most of the time. Their occasional appearances as fruit bodies attests to their hidden presence. Working unseen, they are essential to the functioning of Earth's terrestrial ecosystems, and without them we could not survive. They allowed plants to colonize land over 450 million years ago, they feed our plants, they breakdown dead material. They provide a major food source for many invertebrates and small mammals in nature, and are important in our food industry. Fungi also produce many "wonder drugs" including statins, to control cholesterol, cyclosporine, to prevent transplant tissue rejection. They are also used in the production of some contraceptives and anti-inflamatories, and so the list goes on.