Bongos or bongo drums are made up of two small drums attached to each other. Their bodies are usually made of wood or ceramic with metal tunings. A layer of animal hide is stretched on top of each drum. The two dums do not have the same size—the smaller one is called macho and the larger one is called hembra. They are held between the knees when playing. They generally produce a high-pitched sound when struck by the fingers or palms.