No, you don't have to rush. Serious damage usually takes years of neglecting the swarming episodes each year.
All termites come from a colony - termite colonies are in the ground.
Unfortunately, I don't have a specific name of an exterminator up where you are. And big company or small company, you have to watch out for the sharks - they can be quite adept at cornering fish. Pick a local guy, with a physical location in your local calling area for the best possible service. It has a tremendous reputation for quick and complete control. No, you don't have to rush.