Coloured scanning electron micrograph (SEM) of microorganisms in a sample of wet soil. At centre is a ciliate protozoan with two bacteria adhered to it. Ciliates are single-celled organisms that are covered in hair-like cilia. The cilia are used for locomotion and to move food to the mouth pore. Many different bacteria (yellow, green, blue violet) are seen on the decaying piece of wood. This sample comes from the National Park Northern Black Forest, Germany. Magnification: x4000 when printed at 15cm wide.