Termidor moves only a small distance outward from the site of application before binding tightly to organic matter in the soil. This means that Termidor concentration decreases with increasing distance from the site.
Termites first come into contact with Termidor at the edge of the treated zone as they tunnel through the soil towards the home. At this point, the product is at its lowest concentration. Those termites that do not immediately continue tunnelling into the Termidor treated zone will survive long enough to transfer Termidor to others in the colony through normal feeding and grooming. – Termite Inspection Sunshine Coast
This unique Transfer EffectTM is devastating to other termites not directly exposed to the Termidor treated zone, and indeed may wipe out the entire colony. If termites continue to tunnel into the treated soil where Termidor concentration is higher, they will die more quickly. This means that Termidor is two termite treatments in one.