<prompt> The term animalcules to oral microorganisms is given by:W D MillerLeeuwenhoekRobertsonSocransky  <response>: Animalcule little animal, from Latin animal the diminutive suffix -culum is an old term for microscopic organisms that included bacteria, protozoans, and very small animals. The word was invented by Antonie van Leeuwenhoek to refer to the microorganisms he observed in rainwater. 