The whole water molecule vibrates in three ways: one way like a Mickey Mouse with flapping ears. A water molecule consists of two small atoms of hydrogen arranged in a bent fashion about a larger atom of oxygen. The vibration brings the hydrogen "ears" together and apart. This vibration occurs at the lowest frequency, in the infra-red. The other two vibrations are twice as energetic and involve a stretching of the bonds holding the oxygen and hydrogen atoms together. Even these vibrations, however, oscillate at heat frequencies below what we see.
Vibrating water molecules