I enjoy reading this post, dear. This post reminds me of my junior high school days when I was studying Biology. I advise you to examine standing water in bottles, then the cleanliness of drinking water and moss. Maybe that will be interesting.

I would love if you pour in some suggestions about what other experiments we can do that can interest my 5 year old kid.

Sometimes looking at small objects through a microscope makes us always wary of what we consume. Like the research on snack drinks that we have researched, we are reluctant to consume them again. That's because it looks like there is a kind of clear worm moving around in it.