Tardigrades walk like insects 500k times their size
With a few minutes of googling the only reference i can find says that Tardigrades have approximately 200 neurons in their brains [1] and their dry weight is on the order of one microgram [2].  They also have a lower count of synaptic connections (from the same paper):>Thus, miniaturisation of the tardigrade nervous system is achieved largely by reducing cell numbers, neuropil branches and the number of synaptic connections, while, at the same time, increasing functional specificity. Nonetheless, given the proximity of synaptic neighbours, these adaptations are unlikely to compromise functionality to any great degree.Now go to YouTube and search for videos of tardigrades operating in their environment.  Here are a few examples:https://youtu.be/bVDtzHM2-QQhttps://youtu.be/kux1j1ccsgghttps://youtu.be/slYQTMUz62sI'm blown away by the complexity of their interaction with the environment and the stark simplicity of their neurological wiring relative to anything else that I can think of.  For me it also raises the question of whether they have any subjective experience approximating what we describe as consciousness, or if the entirety of their life is just a long form electro-chemical reaction of deeply nested feedback loops programmed into ~55 million base pairs.Either way it’s simultaneously amazing and humbling.1 - https://bib-pubdb1.desy.de/record/401705/files/Martin_et_al....2 - https://benthamopen.com/contents/pdf/TOZJ/TOZJ-3-1.pdf