Under decent conditions, with a relatively unlimited food supply,
bacteria, yeasts, and fungi can double their numbers every twenty to
thirty minutes, increasing geometrically: 1, 2, 4, 8, 16, 32, 64,
128, 256, 512, 1,024, 2,048, 4,096, etc. In only four hours one cell
multiplies to over four thousand. In three more hours there will be
two million.

For food, they consume the compost heap. Almost all oxygen-breathing
organisms make energy by "burning" some form of organic matter as
fuel much like gasoline powers an automobile. This cellular burning
does not happen violently with flame and light. Living things use
enzymes to break complex organic molecules down into simpler ones
like sugar (and others) and then enzymatically unite these with
oxygen. But as gentle as enzymatic combustion may seem, it still is
burning. Microbes can "burn" starches, cellulose, lignin, proteins,
and fats, as well as sugars.

No engine is one hundred percent efficient. All motors give off
waste heat as they run. Similarly, no plant or animal is capable of
using every bit of energy released from their food, and consequently
radiate heat. When working hard, living things give off more heat;
when resting, less. The ebb and flow of heat production matches
their oxygen consumption, and matches their physical and metabolic
activities, and growth rates. Even single-celled animals like
bacteria and fungi breathe oxygen and give off heat.

Soil animals and microorganisms working over the thin layer of leaf
litter on the forest floor also generate heat but it dissipates
without making any perceptible increase in temperature. However,
compostable materials do not transfer heat readily. In the language