Why do children play with saliva to prove that it will rain in a few days?

That's true! I don't know this question either! The history of my two babies is like this! Pout and eat bubbles as a prelude to rain in a day or two! Observed several times! Children are like an innate warning! This may all be caused by self-contained air compression or something that causes the baby to keep blowing! The same is true of friends with babies.