there are a few qualities of soil animals that are found in almost
all of them. If we are aware of the general characteristics of soil
animals we can evaluate our composting and gardening practices by
their effect on these minuscule creatures.

Compared to the atmosphere, soil is a place where temperature
fluctuations are small and slow. Consequently, soil animals are
generally intolerant to sudden temperature changes and may not
function well over a very wide range. That's why leaving bare earth
exposed to the hot summer sun often retards plant growth and why
many thoughtful gardeners either put down a thin mulch in summer or
try to rapidly establish a cooling leaf canopy to shade raised beds.
Except for a few microorganisms, soil animals breathe oxygen just
like other living things and so are dependent on an adequate air
supply. Where soil is airless due to compaction, poor drainage, or
large proportions of very fine clay, soil animals are few in number.

The soil environment is generally quite moist; even when the soil
seems a little dryish the relative humidity of the soil air usually
approaches 100 percent. Soil animals consequently have not developed
the ability to conserve their body moisture and are speedily killed
by dry conditions. When faced with desiccation they retreat deeper
into the soil if there is oxygen and pore spaces large enough to
move about. So we see another reason why a thin mulch that preserves
surface moisture can greatly increase the beneficial population of
soil animals. Some single-cell animals and roundworms are capable of
surviving stress by encysting themselves, forming a little "seed"
that preserves their genetic material and enough food to reactivate
it, coming back to life when conditions improve. These cysts may
endure long periods of severe freezing and sometimes temperatures of