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 ?

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

To suit animals that live in the soil, the soil should have certain characteristics that provide a suitable habitat for them. These characteristics include:

1. Moisture: Soil should contain an adequate amount of moisture to support the organisms living in it. It should neither be too dry nor too waterlogged.

2. Nutrients: Soil should be rich in organic matter and nutrients like nitrogen, phosphorus, and potassium. These nutrients are essential for the growth and survival of soil-dwelling animals.

3. pH level: The pH of the soil should be within a range that is suitable for the specific organisms living in it. Different soil-dwelling animals have varying pH preferences.

4. Texture: The texture of the soil should allow for burrowing and movement of the animals within it. Soil with a good balance of sand, silt, and clay is ideal.

These characteristics are important because they directly impact the survival and functioning of soil-dwelling animals. Moisture provides hydration, nutrients are necessary for metabolism and growth, pH affects various biological and chemical processes, and texture determines ease of movement and availability of spaces for burrowing.

Based on these characteristics, the most suitable soil for soil-dwelling organisms is known as loam soil. Loam soil has a balanced mixture of sand, silt, and clay, making it well-draining, moisture-retentive, and rich in nutrients. It provides a favorable environment for various types of soil-living animals, such as earthworms, insects, and microorganisms.