Methane is the primary component of natural gas. Other natural sources of methane include permafrost, termites, oceans, bodies of fresh water, wildfires, mud volcanoes, decaying matter in wetlands, digestive processes of animals, and underground and underwater deposits of methane called methane clathrates.ethane is the primary component of natural gas. Other natural sources of methane include permafrost, termites, oceans, bodies of fresh water, wildfires, mud volcanoes, decaying matter in wetlands, digestive processes of animals, and underground and underwater deposits of methane called methane clathrates.