This is interesting, pouring vegetable oil in the pool of stagnant water can prevent the larvae from hatching.

https://hawxpestcontrol.com/how-to-treat-standing-water-to-prevent-mosquitoes-in-your-yard/#:~:text=Applying%20vegetable%20oil%3A%20Placing%20a,larvae%20to%20breathe%20and%20feed.