system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Can intelligent microscopic life exist?

I know "intelligent" is relative so let's say as smart as humans, for example. Is there a size limit for intelligent organisms? Seems like in our planet microscopic organism aren't very smart but can we know for sure? Like Tardigrades might be as intelligent as a dogs. We don't know. Do we?
gpt
Everything we "know" about "life" has to be qualified with the phrase "as we know it".

Life as we know it requires a certain degree of biological complexity to be intelligent, something microorganisms don't have. But we can't say for sure it's impossible; just that we certainly haven't found any examples of it, or evidence for it.