Wednesday, April 8, 1998 Published at 22:08 GMT 23:08 UK
Termite 'mothball' keep insects at bay
Naphthalene has never before been found to be used by insects
Mothballs were not the invention of house-proud humans. Termites have been using their equivalent for years.
According to researchers, a species of termite fumigates its underground nests with naphthalene, the active ingredient in mothballs.
The Formosan subterranean termite, Coptotermes formosanus, mixes the chemical into the soil and chewed-up wood which it uses to insulate the complex of tunnels in which it lives.
The fumes are thought to keep away the termite's natural enemies such as ants, poisonous fungi and nematode worms.
Scientists are mystified as to how the termites incorporate naphthalene into their nests and why they themselves are not affected by.
They carried out tests on one of the subterranean termite's greatest enemies, Solenopsis invicta, or fire ant and found the ants were immobilised at concentration levels that had no visible effect on the termites.
The discovery, reported in the science journal Nature, is the first time naphthalene has been found naturally associated with any insect species.
The chemical is traditionally used to repel moths and carpet beetles from clothes. It also has antiseptic properties.
Although traces of the substance have been found in magnolia flowers and in a gland on the forehead of certain deer, human users must use industrial chemistry to obtain it.