Diatomaceous earth is a less toxic way to treat termite infestations than traditional pesticides. The diatomaceous earth swells inside the termites' digestive tracts when they eat it, making them unable to eat enough food to live, so they starve to death. The earth, often used in combination with silica aerogel, should be administered by a professional, as both substances present respiratory hazards. Many times, professionals install the chemicals in traps as bait to limit the spread of the substances.
Diatomaceous earth is highly effective on ground termites as well as drywood termites. The substance is often mixed with boric acid, which dries termites out from the inside and creates a coating inside the termites that prevents them from shedding their outer skeleton, eventually killing them.
The way to apply these treatments if not using a professional is to mix two cups of boric acid with one cup of the earth. Both are powders, so wood should first be treated with an oily substance to hold the powder in place. Then, use a sieve to apply the powder, giving wood surfaces a thin coating. Do this for all areas where wood is infested.
When termites come into contact with the powder, they then track the powder with them when they return to their colonies, where it infects the whole colony.