Subterranean termite colonies may contain hundreds of thousands of individuals, foraging in many different directions. For the homeowner, localized or “spot” treatments are generally a gamble except in cases of re-treatment. Most reputable pest control firms will not warranty spot treatments, since it’s likely that termites will eventually find other points of entry into the structure.
Some companies may offer to do a so-called “perimeter” treatment, using one of the non-repellent liquid products (Termidor, Premise, etc.). Typically this will involve a thorough application around the entire outside foundation wall of the building, and spot-treating any infested or high-risk interior areas.
If the homeowner is considering such a treatment, they should inquire whether it will be accompanied by a service agreement in case termites return. (Service renewal agreements usually state that if termites return, the company will return and retreat the affected areas at no additional charge provided the renewal agreement is maintained.) It’s a bit of a gamble to purchase any termite treatment option without an ongoing service agreement or damage repair warranty.