The Pnumann: mites with hydraulic brains
You would be remiss if you thought that sentient life is constrained to a single order of magnitude when it comes to size. The "pnumann" are a sentient species of carbon-based life forms whose physical size is on the scale of house dust mites. They live in nutrient-rich liquid environments at normal human-relatable temperatures. Besides their tiny size, their main claim to exoticism is how their brains work: they "think" using hydraulics. Since their very existence is based on the flow of liquid, their technology is about one order of magnitude smaller than the technology we humans use. They have an intimate understanding of small things, including microbes, which are about the size of small ants to them. One of the pillars of pnumann culture is personal space. Since their hydraulic brains have no real boundary separating them from the water they exist in, it is only in very personal situations that pnumann will get within one "brain length" of each ot...