Their colonies are often quite visible - one fungus ,in fact, is far and away the biggest organism on earth - about four square miles in size, albeit mostly underground.
But microscopes have been around for hundreds of years, so viewing the tiny microbes as a single individual isn't an unsurmountable problem.
But the microbes' second secret is that they seem extraordinarily boring and stupid if seen alive by an ordinary light microscope and hardly less boring if seen dead and stained by a high powered electron microscope.
We need the chemical probes of chemists to reveal the hidden complexity buried inside them - the thousands of literally Earth-sustaining enzymes that only microbes - and not Man - have.
Mother Earth can live without Man - but not without the Slime
Remove Man and the Earth would go on, in far better shape than she is right now.
Remove the microbes (and their Earth-sustaining invisibly small enzymes) while keeping all other life and soon Earth would be as barren as Mars.
If you vote Conservative or Republican, you probably don't believe any of this.
At least not without suffering a nervous breakdown.
Like H P Lovecraft, your mental health literally depends upon believing in a rigid hierarchy with Man on the top and woman on the bottom, followed by children, darkies, the deformed, degenerates, animals, plants.
Way way way down at the very bottom are the microbial slime, the horrible slime ....