This video shows Strike Force Pest and Termite Control Inc. performing a trench and treatment for Subterreanean termites. This put a termiticide barrier around your home.
Doing it myself but the cost makes sense, dig down to the foundation around your place it'll take close to 2 days by yourself. Add materials (costs $200 for just 1L fiprinol), equipment, ppe and risk of damaging pipes/electrical . It's pretty labour intensive and most trades don't charge less than $100 an hour because of overheads.