Nothing strikes fear into a homeowner's heart quite like termites. George D. Lepp/Corbis (© George D. Lepp)Click to enlarge picture

Nothing strikes fear into a homeowner's heart quite like termites. George D. Lepp/Corbis

Nothing strikes fear into a homeowner's heart quite like termites. And no wonder: These little buggers annually cause about $5 billion in damage to U.S. buildings, according to a National Pest Management Association estimate.

And almost nobody's immune: Termites live in every state except Alaska. Even the White House and Statue of Liberty have had termite problems in recent years, says Mike Potter, a professor and urban entomologist at the University of Kentucky.

Here's how the experts say you can tell if you've got them, how to get rid of them — and how to keep them away for good.

First, a word on the enemy
Termite colonies are decentralized, spaghetti-like things that can range from 10,000 insects to a million – and could have reached over from your neighbor's yard a half-acre away.

There are, broadly speaking, three groups of termites in the U.S. that damage homes: subterranean, drywood and dampwood termites. The first two are the most damaging to buildings, says Potter, who wrote the book on termites (the chapter in the definitive "Handbook on Pest Control").  Subterranean termites are the most widespread, so the advice here focuses on them. (Drywood termites, which live above ground, are mostly a problem in coastal areas, especially in parts of states such as Florida, California, Louisiana and Texas.)

Discuss:  Tell us: What's your secret for battling termites?

5 signs you have termites
The first step, of course, is finding out if you have a problem. Your first option is to call some pest-control companies; they'll frequently perform free termite inspections in hopes of finding a problem they can remedy, says Potter. But you also can survey your home yourself. Here's what to look for:

1. Swarming. Swarms are what tip most homeowners off to an infestation, says Potter. "That's probably the most visible indicator that you may have a termite problem." Swarms usually happen in the spring, when some of the termites take flight from the colony in an effort to establish a new colony. A homeowner with a termite problem will often find their bodies lying on sashes and below windows where the termites have tried to exit.
 

2. Shelter tubes. Subterranean termites need moisture to live, and they need the protection of tiny spaces. So they build pencil-thick tunnels of mud and earth across exposed areas. To see if these tubes are active, break one off and see if it is rebuilt, says Susan Jones, associate professor of entomology at Ohio State University.
 

3. Bugs. Simply pull back mulch around suspicious areas of the house or rotting wood near the house and look for termites.
 

4. Hollowed wood. Probe suspect wood with a knife or flat-blade screwdriver to see if it's been hollowed, Jones says. Severely damaged wood may sound hollow when tapped.
 

5. Dirt in wood. Also, homeowners sometimes get confused about what is water damage and what is termite damage, since water and termites are often related. "The best way to differentiate termite damage from moisture damage is that termites bring bits of dirt up into the wood," says Potter.

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Where to look
"Basically, termites are constantly foraging for food and moisture, so much of their search is random," explains Potter. In other words, termites haven't sniffed out the buffet at your home, but have stumbled into it by blind luck —though once one termite finds choice eating there, it carries the word back to the colony.

To fight the insects, it helps to know where they're marching in:

  • Think like a bug. Termites don't need to chew through exposed wood to enter a home. "They can get in through all sorts of cracks and crevices where the house meets the foundation," says Potter. Look for them at these weak points in the home's perimeter: plumbing penetrations, settlement cracks in concrete foundations, front entry doors and around garage openings where a door accesses a crawl space.
     
  • Follow the water. "Moisture is probably the No. 1 draw for termites," says Potter. So look in areas beside the house where moisture holds — under leaky faucets or around air-conditioning units — "anything that lets water puddle close to the foundation."
     
  • Dive into the woodpile. "Another (favorite termite hangout) is where there's a lot of wood debris. That's why we tell people not to stack wood against their house — it's like putting out a steak for termites," says Potter.

Getting rid of the problem
So you found 'em. Don't panic. Though termites work 24/7, your house won't collapse tomorrow; they are actually slow eaters. "The average termite colony can eat a pound of wood in five years," says Richard "The Bugman" Fagerlund, a syndicated newspaper columnist and author of books including "The Bugman on Bugs: Understanding Household Pests and the Environment."
You have time to figure out the right course of action. "But of course that depends on where the wood is – if it's baseboard wood, it's no big deal," Fagerlund points out.

But Potter has one piece of advice: Call in a professional. "Unless there's just a mailbox post that a homeowner can take on by himself with materials from the hardware store, this is not something you want to do yourself," he advises. "It's one thing to kill termites, it's another thing to get rid of an infestation entirely."

With that settled, a homeowner has two main battle strategies: liquid and baiting.

The liquid method: An exterminator injects termiticide into the soil around the house and other areas to deter termites from entering and defeat those that have already gained access. The insects carry the insecticide back to others in the colony. All eventually die. The process involves a technician coming to the home with a tank and an injector, and likely drilling some holes in patio slabs and even drilling a few inside the home to "create a continuous liquid-treated zone around the foundation of the house," says Potter. "We have some phenomenally effective liquid products today" so that large amounts of poison are no longer needed, and much less drilling inside the home is necessary, he says.

According to the National Pesticide Information Center, a common ingredient in termite pesticides such as Termidor or Fipronil can cause short-term skin or eye irritation for those who come in contact with it. And ingesting it can lead to vomiting and dizziness. Rats who were fed increased doses for two years developed thyroid tumors, making it a possible human carcinogen.

But this kind of exposure is far from normal for something that’s injected into the ground and applied in small doses compared to yesteryear, says Potter.  "People should not be concerned about the dangers of a properly performed termiticide application."

Pros: Results are quicker than other options.

Cons: It's more invasive and requires more insecticide.