Swarms

• On occasion, you may see winged ant-like insects --- as few as 10 or, for some species, as many as thousands --- flying inside or outside your home. All species seek warmth, so they're especially likely to be seen around light fixtures or pouring out of a hot attic. These are only a spinoff colony, however, setting out in search of new territory. The soldiers guarding the original colony and the workers doing the actual chewing stay hidden.
  
  

Insect Debris

• At the end of their swarm, the termites lose their wings, and a pile of these gossamer teardrops is an ominous sign that the insects have chosen your house to make their home. If they've dropped them outside, it's less worrying. At any time, you may also find piles of granular feces, looking something like tiny grape seeds. Look for a hole or other sign of the colony at the point where the granules have fallen out of your wall, ceiling or cabinets.
  
  

Wood Damage

• Termite damage has a kind of beauty in cross-section, as long as it isn't in the beams that hold up your house.Hemera Technologies/Photos.com/Getty Images
  
  Termites want to keep their environments warm and moist, so they avoid chewing clear through to where you can see their tunnels. Instead, they tend to leave "blisters" as thin as veneer, which may not even swell or discolor so you can notice them. If you can see the runs, it's probably old damage from a colony that's moved on or been killed. Fine sawdust, however, is a sign that there may be an active nest behind that baseboard or under the window frame. Poke at suspicious areas with a thin knife or a finishing nail; it won't go into sound wood with just the pressure of your hand.
  
  

Mud Tubes

• Only one species of termite that lives in North America makes visible mud structures, but these subterranean termites live in all of the lower 48 states and Hawaii. They find the moisture for their nests in the soil, particularly against the foundations of buildings where they can feed, and they may build tiny tubes out of mud for access into the buildings. Look for pencil-sized trails across masonry, especially where there are cracks, which the termites may also fill with mud.
  
  

Make Sure They're Still There

• Ask the inspector to show you evidence of an active colony before you panic or sign a contract for extermination. Damaged wood by itself may not be sufficient evidence; live insects under wood blisters or inside mud tubes when you break them are much better proof.