What are Microfauna?
Microfauna are small animals and unicellular organisms visible only under a microscope. Usually microfauna is defined as creatures smaller than 0.1 mm (100 microns) in size, with mesofauna as organisms between 0.1 mm and 2 mm in size, though definitions may vary. In the soil, microfauna can be found in large numbers — generally several thousand per gram. Anyone can take a bit of wet soil, put it under a microscope, and find microfauna. Some of the most common and important microfauna are protozoa (unicellular eukaryotes), mites (among the most diverse and successful of all animals), springtails (related to insects), nematodes (transparent wormlike creatures), rotifers (named for their wheel-like ciliated mouthparts), and tardigrades, also known as “water bears,” one of the hardiest organisms in nature. Microfauna can be found worldwide, wherever there is wet soil, and some other places as well. Springtails have been found in the McMurdo Dry Valleys of Antarctica, one of the coldest and
