Like spiders, ants come in many shapes and sizes as well in NC. The most common being the fire ant and the odorous house ant. Both can be a pain to try to get rid of on your own if you don't understand how these ants behave.
Fire ants rarely forage beyond the exterior perimeter of their mounds and rarely forage into your homes, but it does happen! For this reason fire ants allow the food to come to them in which they swarm out from the mound and attack their prey. We place greasy baits around the mound in a circle to allow the ants to find it themselves or they may not eat it. Then we cover the yard however the label may state and protect the rest of the area from being the victim of more spread out fire ant mounds.
As for the odorous house ant, it is the most common ant in the state but it does look like and sometimes act like other common species like the pharaoh ant and the little black ant. Odorous house ants are much easier to identify though and by simply smashing the ant, it will release a pungent odor similar to that of rotting coconut.
Odorous house ants are every where outside much like any other ant, making it near impossible to eradicate them entirely from a property. But once a house ant issue is solved, general maintenance can be performed with a combination of liquid application and bait to ensure it never happens again.
As for the ant issue you may deal with every single year at the same exact time, it may be resulting in an issue you haven't recognized. The reason ants invade the same spot repeatedly is because nothing can remove the chemical pheromone they release to leave a trail behind. So year after year when the trail moves into the kitchen and a store bought bait trap is placed what's really happening is they find the bait, they take it all home back to the nest and once the bait runs out they appear to be gone. But really they have taken all the bait and only killed off a small number of the nest while the whole time the nest has really just increased in size and possibly worse, taken harborage in a wall void or the crawlspace.
So yes, the nest never did die if you continue to have the same issue year after year. Why deal with that when we can take care of the issue once and for all. Don't be content with an issue, be happy with Enfocus!