what should soil have to suit animals which live in soil?why are these things important?hence, infer which type of soil is most suitable for soil living-things ?

Answer 1

Wondering if you include insects, and reptiles as "animals". If so, soil has to be stable, but not hard rocks, and has to retain moisture , animals need humidity about the same as humans. Some insects need soil of a pH range to survive, an example is the Western Alkali bee, found in the salty soils of Texas, Arizona, New Mexico, and California These insects are the prime pollinator of Alfalfa. https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/alkali_bee.shtml