The application of a liquid pesticide, known as a termiticide, to the soil. The goal is to create a continuous chemical barrier around and beneath the structure in order to block all potential routes of termite entry. Termites attempting to penetrate through the treated soil are either killed or repelled. A typical "barrier" treatment may involve many of gallons of dilute termiticide solution injected into the ground alongside the foundation, beneath concrete slabs, and within foundation walls.