What can be poured on top of stagnant water to kill the mosquito larvae?

Standing water breeds most of the mosquitoes and mosquito-borne diseases. As we know, oil doesn't absorb in water and if we pour oil on top of the water it will cut the oxygen supply necessary for the larvas to grow. So, by adding oil to water, the mosquito larvas in the stagnant water will not have enough oxygen and subsequently, they will die.