When you purchased your current home, it was most likely inspected for termites. You would have received a document from an inspection company to certify that no active infestations were present when you bought the home. Unfortunately, that doesn't mean your home doesn't have termites. If you haven't kept up termite treatments, it's always possible that they might have entered your home.

Spotting a termite infestation isn't difficult, if you know what you look for. And of course, sometimes the signs are unmistakable: an indoor swarm is perhaps the most definite sign that an active infestation is present in your home.

There are three main signs to look for if you're trying to determine whether your home is infested: damage done to wood, mud tubes, and indoor swarms.

Damage done to wood, drywall, and other materials might seem like the most obvious sign of termite infestation, but strangely, it is often the easiest to overlook. Termites eat from the inside, so the damage done is often not visible. Don't assume that your home is free from termites simply because you cannot detect any signs of damage.

Signs of termite activity may appear in the form of pin holes in wood or drywall, but there may be no outward signs at all. If this is the case, try hitting wood you suspect to be infested with a hammer or other implement: hollow sounds are a sign of termite activity. If you do hear hollow sounds, try gently probing wood with a screwdriver or icepick-if it's infested, it will be soft and may break apart easily.

Prime places to check for infestations are in basements, and in structural beams above cellar walls. Any locations near furnaces, hot water heaters, and chimneys-any area that gives off warmth-will also be ripe for infestation.

Termites are largely subterranean insects. Those species that live underground must travel from the termite subterranean colony to their food source in order to feed. If a termite colony must do this, it will build tiny tubes made from mud to provide the insects with shelter when they are traveling from the colony to the food.

Look for tubes in locations such as wooden posts, exterior masonry, trim around windows and doors, and cellar walls. These mud tubes are very distinctive, simply appearing as small thin tubes (around the thickness of a pencil) made from mud.

It's not possible to tell simply by looking whether an active infestation is present, however-if you spot mud tubes, they may be left over from a prior infestation. To determine if you have an active infestation, you'll need to break open some of the tubes and check for termites.

Indoor swarms are easily the most obvious sign of a termite infestation if you should happen to experience one. However termite colonies only swarm every few years, so it's not something you can expect to see if you go looking for it. The more likely scenario is that an unexpected termite swarm will alert you to the presence of an infestation.

Termites swarm during the reproductive phase of their life cycle-usually early in spring. During the warmest, sunniest days, a termite colony may swarm. A swarm will usually occur following rain, but this depends on the species: different species of termites tend to swarm at different times. Drywood termites, for example, most often swarm after dusk, while subterranean termites usually swarm between mid-morning and mid-afternoon.

Regardless of the species of termite, a swarm generally lasts several hours. During a termite swarm, the insects will travel from the colony a short distance before seeking cover to mate. Most die before mating, if a swarm occurs outdoors. Any termites that do manage to mate will become the founders of a new colony that will grow for several years before swarming.

Swarms that occur outdoors are not usually noticed. If termites swarm inside your home, however, the signs are unmistakable, particularly if you are actually present in the room at the time. Indoor swarmers will emerge from a wall and fly towards light sources-doors, windows, and even light bulbs. If nobody is present when the swarm occurs, the signs are still difficult to miss, as thousands of dead termites cannot easily be overlooked. You'll also likely find large numbers of wings at or near sources of light.

If you detect any signs of infestation, the next step is having a professional inspector come to your home to confirm that the infestation is an active one. Treating your home will come after that-but don't panic if you can't get all of this done immediately. Termites feed very slowly, and waiting a month or two to treat your home won't cause much extra damage.