What is the smallest animnal in the world…. would an animnal be considered a bug?
Animals are defined as multi-cellular, and attaining sustenance through eating other organisms (rather than producing their own nutrition through photosynthesis like plants). Thus, amoebae and bacteria are not animals (they are not multi-cellular), and while the tiny fish are indeed animals, they are not the smallest animals – there are many insects and other critters that are multicellular animals that are much smaller than them. As far as the smallest multi-cellular animals, it’s sort of a tie between Tardigrades (sometimes known as water bears) and Rotifers (also known as wheel animals). Both groups are definitely animals, and can be as small as 0.1 mm long. In fact, many of them are actually smaller than amoebae (which are single-celled).
