'''Methane''' is a [[chemical]] substance CH<sub>4</sub> found in a high percentage in [[natural gas]]. It is also a common byproduct of [[digestion]] in human and [[animal]]s. | '''Methane''' is a [[chemical]] substance CH<sub>4</sub> found in a high percentage in [[natural gas]]. It is also a common byproduct of [[digestion]] in human and [[animal]]s. |