Of the many different varieties of mold, black or green, that can live in your house, one of them, stachybotrys, throws off spores that, once inhaled, can lead to the symptoms of "sick building syndrome:" burning eyes, headaches, fatigue, and more.

Though small patches of mold can be treated with a diluted bleach solution, big areas call for professional treatment. The trouble is, you may not know when you have big patches because mold likes to grow in dark, hidden areas like corners, behind wet wallboard, or under your floorboards. If you don't want to get down in the basement or in the crawl space under your floor with a flashlight, you'll have to hire an inspector to do it. It should be easy enough, though, for the average homeowner to pull appliances away from the wall and look inside floor-level cabinets for signs of mold. Likewise, it takes only a slight push on drywall to tell if it's wet on the other side - there will be some, possibly a lot, of give. You may go right through it. Mold's Preferred Environment: Mold Loves to Get Down and Dirty

Molds thrive on moisture, which is why New Orleans, in the wake of Katrina, turned into a giant Petri dish growing mold inside buildings everywhere. But you don't have to live in the wake of a flood or even in a humid area to have a mold problem. You can get it if you have leaks in your house or if you have a central air conditioning system; cold air running through ducts is especially good at producing mold because it alternates between high humidity and low humidity, just what mold thrives on.

Mold also needs dirt to flourish; keeping your ductwork clean and patching any leaks where dirt can get in will cut off mold growth. The same goes for keeping dust from building up in places like the space under your refrigerator. Change the filters in your heating/air conditioning system frequently, using the newer filters that are more effective at catching small particles than the old fiberglass models.

Should you get dirt buildup in your ductwork followed by mold, you've got yourself a big problem. If the ducts are lined with a fiberglass surface, it's even worse because nothing can be done except to tear them out and replace them. Mold leaches into fiberglass linings. Where to Find Mold: Look for Your Mold in All the Right Places

As for dirty ducts that are not lined with fiberglass, a number of professional services have been developed to clean them out (be sure to check out such mold clean-up services before committing to one - there are fly-by-night operators in this business), but only one seems to be effective on a consistent basis. It involves running a fiber optic television camera into the ducts to locate the areas of dirt. These areas are usually moist, sticky and resistant to all but the strongest removal methods. Holes are cut into the ducts at the spots where the dirt is found and a strong suction hose reaches in and pulls out the dirt. How do you find out whether you have mold?

What should you do if you suspect you have it? Daniel Friedman provides an excellent and thorough guide for dealing with household mold. The procedure he lays out - in more detail than presented here - follows these steps:

1. Reduce your exposure. If you have a damp, musty basement, don't use it for anything more than storing sauerkraut. Stay out. 2. Find the mold. In particular, check for leaks; you'll generally find mold. 3. Clean up the mold. 4. Check areas that hold the potential for forming mold. Correct them.

Friedman believes that the average handyman can take care of small mold problems. "You don't need to hire an expert to clean up moldy bath tiles or a square foot of moldy drywall." But, he says, be alert to the possibility of unfortunate discoveries large enough to warrant calling in a professional.

Should you be building a house or an addition to a house, there are things you can do to reduce the possibility of mold attacks. Some drywall sheets, for instance, are now manufactured using a material impervious to mold rather than paper. Metal framing does not absorb water like wood framing. Keep interior materials dry. If materials are stored outside, cover them with loose tarps (to insure air flow) and keep them off the ground. Make sure any wet materials are fully dried out before installing them.