There are a few organic ways to kill off termites. This way you won’t need to use harmful chemicals.
Because termites dig through the ground, use sand, basalt or other rock types to build a barrier around your house.
Because termites usually built their mounds in a north to south pattern, you can use a magnet to disturb the magnetic field of the mound and most likely make the termites move.
To increase the chance of natural termite predators, like spiders or frogs, you can plant trees and shrubs around the area you want the termites to stay away from.