Soil zoology or pedozoology is the study of animals living fully or partially in the soil (soil fauna). The field of study was developed in the 1940s by Mercury Ghilarov in Russia. Ghilarov noted inverse relationships between size and numbers of soil organisms. He also suggested that soil included water, air and solid phases and that soil may have provided the transitional environment between aquatic and terrestrial life. The phrase was apparently first used in the English speaking world at a conference of soil zoologists presenting their research at the University of Nottingham, UK, in 1955.^[1]