By Christina B. Farnsworth. It's a jungle in there. In a typical house, dust mites and silverfish set up housekeeping, feeding off the ounce of skin cells each person sheds in a month. Mold, bacteria, and yeast co-exist with poisons leaching from certain building materials. And underneath it all, newer, so-called safer poisons, only slow down--not stop--termites from munching their way into homes.

Last year the Georgia Department of Agriculture alerted more than 4,100 metro-Atlanta homeowners that their homes were vulnerable to termites--a pest-control company was allegedly at fault, but that is not always the case.

In termite country, a single-family home may sit atop four termite colonies. Once termites enter, they leave a trail for others to follow. In 1988, concerns about environmental and human health effects stopped the use of chlordane and heptachlor (poisons effective for 30-plus years), says H. Alan Mooney. Newer chemicals last only five to seven years, and great care must be taken to leave treated areas undisturbed after application. "The objective," Mooney, president of the Portland, Maine-based Criterium Engineers, says, "is to establish a continuous horizontal and vertical barrier between the home's wood and termites in the soil."

And then there's the arsenic-based preserved wood, but that's another story. (See "Phase Out!")

Home inspector Jeffrey C. May, author of My House is Killing Me!, reports dust mites and mold like the same humid environments. Some mites even dine on mold. Mold irritates lungs, even in folks not otherwise allergic. Some remediation companies are killing mold by tenting buildings and heating to an interior temperature of 160-degrees F.