The program is about the natural history of this invisible world: the things that float in the air around us, the microbes that live in the dish cloth on the kitchen counter, the fungi under our fingernails, and the visitors in the saucer under a house plant.

There is a growing number of people who regard marijuana (cannabis) as a benign medicine, offering relief to people suffering from a variety of illnesses, including epilepsy, arthritis, multiple sclerosis and glaucoma as well as lessening the side effects of medications and treatments given to cancer and HIV patients. CBC Television's THE NATURE OF THINGS with David Suzuki examines the medicinal uses of marijuana.

It is only recently that humans have become aware that animal communication is often elegant, elaborate and subtle. Understanding how other species communicate tells us a great deal about the history and evolution of our species.