Microscope sophont

From 2speccers2tools wiki

This sentient micro organism wages war on the sapients that rule elsewhere,blocking their noses with tiny space ships and taking submarines down what would be a blood vessel for a single cells organism,bursting the ribosomes,and making the fauna susceptible to leaks. They have also colonises other planets,forming a type two civilisation,but unable to do anything to the environment in practiceas larger fauna dominate.