Termites are outside in everyone's yard, just a fact of nature. The trick is to keep them out of your house, and if you never treat, you'll probably eventually get them. It's easier to put up a barrior to keep them out than to get rid of them once they are in your walls, where you may not discover them until they've done significant damage.
The best thing on the market right now according to my brother who is in the chemical supply end of the industry is Termidor.
For Termite Control | Termidor Termite Defense, America's #1 Termite Defense Product
It's not toxic to humans or pets, and doesn't kill on contact. It gets on the termite's body and then they pass it along to every termite they touch, then they all die from it. It protects for about 10 years. You can do it yourself and save a thousand or more. If you don't have do-it-yourself pest control stores in your area you can buy it online. I got it here:
Termidor SC, Termador, Termidor Termite - FREE SHIPPING
Although the Termidor instructions tell you to dig a 6x6 trench around your property and fill it with the liquid mix, my brother told us the pros you pay just push a flat shovel into the ground against the foundation and pull back, making a narrower trench right against the house, then they spray the foundation, the trench, and the dirt that goes back into the trench, using less of the mixture than the sites tell you to buy. We kind of did a combination of the two methods... dug a narrow trench and flooded it and the fill dirt with liquid mix, and also sprayed wooden window trim. It also kills ants the same way.