Where did the water go?

This is a random thought I had the other day so take it for what it’s worth but let me describe to you a situation.

Imagine there a group of human ancestors a long time ago when they were still extremely primitive and only had a limited amount of tools. Say this also includes the ability of collecting water in large containers for whatever easy access they needed rather than having to collect it from a stream everytime. Let’s say that they collected this water right before they slept and left it out. The next day they all woke up late and realize that a noticeable amount of the water is gone. Presumably this is due to evaporation (though I’m not really sure how fast it would evaporate).

What would they think this is because of when they realize such is the case? Would they think someone else stole some of it? Or would they attribute it to some higher being and create a religion based off of it?

This is a random thought I had the other day when I accidentally spilled a lot of water in the kitchen when refilling a Brita filter container late at night. I decided not to wipe up the water and let it dry by morning.