Given the level of damage termites can do to a home, it's no wonder you are worried. The good news is, there are things you can do to stop or prevent termite infestations.
First, you need to find out whether your home does have termites. Finding one outside the house is not a definite sign of infestation, but it is best to check your home and its immediate surroundings to make sure.The attic and basement are the best places to start. Examine all wooden structures, especially timber, and also check carpets, paper (including money!) and any clothing you may have in there. You'll recognize the damage if you see it. If the damage is solely inside the wooden timbers, the wood will sound 'hollow' if you knock on it.
If you find termite damage, and want to make extra sure there aren't any about, contact your local pest control company (call more than one to get the best price). They can remove any nests, exterminate the termites (likely using boric acid) and give advice on termite prevention. Only small scale infestations can realistically be tackled on your own - ask at your local hardware store for advice.
Preventing Termite Infestations
If you have no termites, but are still concerned about infestation, you can buy termite-resistant materials for your home, and the soil around your home can be replaced with pre-treated soil which is poisonous to termites, ensuring they will stay away. Blocking cracked pipes and caulking your home will also help.
This film should give you a few tips on how you can detect infestation: