Ant Season in South Carolina: When Ants Come Indoors

Clemson places the flight of winged males and females from an established colony in late spring or early summer. On this page that is rendered as May 1 to June 30, which is our reading of a season phrase rather than dates the agency printed. That is South Carolina's own extension service, not a neighbour's. Any single year moves with the weather.

Three characters settle it, and you can check all three on a phone photo. Antennae: an ant's are elbowed and bend sharply partway along, a termite's are straight and beadlike. Waist: an ant has the pinched wasp waist, a termite's body runs straight back with no pinch. Wings: an ant's front pair is longer than its hind pair, a termite's four wings are about equal and roughly twice its body length. Penn State Extension and Colorado State University Extension both publish the comparison, and Colorado State notes that winged carpenter ants are routinely mistaken for termites.

Winged reproductives emerging in numbers inside a building point to a nest inside it, underneath it, or immediately against it. An emergence during winter or early spring points that way most strongly of all, because nothing outdoors is flying then. Swarmers found outdoors, on a porch, on siding, or on the outside of a window, usually mean a colony nearby in the yard rather than one in the house. But note the caution Nebraska Extension publishes: Seeing carpenter ants indoors does not by itself mean the house is infested. One or two winged queens in spring are usually mated females that wandered in from outside looking for somewhere to nest. It is large numbers, and out of season numbers, that mean something.

Carpenter ant, Odorous house ant, Pharaoh ant, Thief ant, Argentine ant, Imported fire ant. The structural one, and the expensive one. Carpenter ants hollow smooth galleries in damp or decayed wood to nest in it. They do not eat it, which is why the pile of coarse sawdust underneath is the giveaway. Which of these you actually have matters more than the season does, because they nest in different places for different reasons. Presence on this page follows the range statements the extension services publish.

No published one. Carpenter ant mating flights are triggered by photoperiod and by changes in temperature rather than by any particular temperature being reached. That is why no agency publishes a number. None of roughly twenty land grant extension services publishes a soil or air temperature threshold, and the numbers that circulate online trace back to pest control marketing rather than to any agency. The live soil temperature tool shows how far spring has come where you are.

Yes, all 46 counties. The whole state is inside the federal imported fire ant quarantine. What the quarantine actually does is restrict moving certain things out of the area: soil, baled hay stored on the ground, nursery stock with soil attached, and used soil moving equipment. In the regulation's own words, "No person may move interstate from any quarantined area any regulated article except in accordance with this subpart." These figures were read from USDA's own federal quarantine service on August 28, 2026 and agree with APHIS Federal Order DA-2025-34. The quarantine changes, so check the APHIS list before acting on it.

Prevention here starts with inspection and with fixing the conditions that make a building attractive, not with a scheduled pesticide application. That is the extension position. In practice that means the moisture and the bridges: Excess moisture is what makes a building attractive in the first place. Fix leaks at attic vents, at pipes and sinks, and around chimneys and skylights, and replace wood that water has already damaged. Trim trees and shrubs back so there is at least a foot of clear space between planting and the building walls or roof line. Store firewood away from the house and off the ground, and carry it inside as you burn it rather than stacking it indoors. Treatment is a licensed activity, and a licensed operator is the source for anything that goes down as bait or spray.

They remove wood rather than consume it, cutting extensive galleries through dead and water damaged timber. The damage is real but slow, usually taking years to become structural. A nest found inside a building is often a satellite of a larger parent colony living outdoors in a tree or a stump, which is why finding one indoors does not always mean the whole colony is in the wall. Carpenter ants do not normally attack sound wood. Penn State Extension puts the practical line at a moisture content below about 15 percent, and UF/IFAS says flatly that they will not excavate galleries in sound wood at all. That is why the prevention list on this page is really a moisture list.