If you can find where they disappear into the wall containing the styrene you might get a syringe or a BBQ sauce bottle with a nozzle and squirt some Eucalyptus oil into the hole. 100-200ml would be enough. The liquid will turn into a toxic vapour that expands to wherever there are air spaces.
2. Check for any hollow trees nearby (up to 40-50 metres). Info on drilling and killing nests in trees is on our website.
3. Check any timber in contact with the soil nearby, there may be a nest under or in it.
4. If you can find a place where the termite tunnels have come up out of the soil to enter the building, this soil area could be soaked with say Bifenthrin following the directions on the concentrate available from most hardware stores. It keeps the soil toxic and impenetrable for 8-10 years.