CH4, or methane, is a nonpolar molecule. Methane is a highly symmetric molecule made up of atoms with similar electonegativities, and consequentially, it has an evenly distributed electron cloud and no regions of significant charge.
Polar molecules contain localized regions of positive and negative charges. Polarity results from the uneven distribution of the molecular electron cloud. Electrons become unevenly distributed when atoms within the molecule have significantly different electronegativity values. Molecular asymmetry can also contribute to polarity. Methane's carbon and hydrogen atoms share the electrons in their bonds almost equally, resulting in only a slight charge differential between the carbon and hydrogen atoms. Methane's symmetric, tetrahedral geometry also contributes to its lack of polarity.