What are Some Common Microscopic Animals?
Microscopic animals are animals that are too small to be seen by the naked eye. Microorganisms such as bacteria are almost all too small to be seen with the naked eye, though these are not qualified as animals. Eukaryotic (complex-celled) unicellular organisms with animal-like characteristics are called protists, but these too are not considered part of Kingdom Animalia (also known as metazoa). True animals are multicellular and have differentiated tissues. Microscopic animals are the most numerous of all animals. If aliens were instructed to take a random animal from Earth, they’d probably grab some type of microscopic animal. Common microscopic animals include planarians (flatworms), numerous mites, including dust mites and spider mites, and aquatic crustaceans such as copepods and cladocerans (water fleas). The most numerous microscopic animals are nematodes (roundworms), rotifers (aquatic filter-feeders), and tardigrades (water bears). Nematodes, in particular, are probably the mos
