Termite Swarmers in San Antonio: What a Swarm Means
A termite swarm is a mating flight: winged termites leave a mature colony to pair off and start new ones. In San Antonio, native subterranean termites can swarm as early as January and February, by day, while Formosan termites fly at night in late spring and drywood termites in late summer. Swarmers themselves do not eat wood, but a swarm inside your home is one of the clearest signs that a colony is working in the structure.
If termites are swarming in your house right now, call or text (210) 281-1064 or book an inspection.
Why do termites swarm? #
A termite colony does not send out swarmers until it is well established. AgriLife's subterranean termite guide (E-368) says a colony usually takes three to five years to mature before producing them. When warmth, day length and moisture line up, the winged adults leave the colony together.
After the flight, pairs land, break off their wings and try to start a colony of their own. Swarmers that came out of your walls tell you the parent colony is close by.
Termite swarmer or flying ant? A quick check #
Winged ants and termites often fly in the same weeks. Catch one and look:
- Antennae: termites have straight antennae; ants have antennae bent at a sharp elbow.
- Waist: termites are thick through the middle; ants pinch in tightly.
- Wings: a termite's four wings are all the same length; an ant's front wings are longer than its back pair.
The EPA's termite identification guide uses the same antennae and wing checks. If you see winged ants inside, they may be carpenter ants; see carpenter ants.
Swarm season around San Antonio, by termite type #
| What you see | Most likely termite | When |
|---|---|---|
| Dark, small swarmers in daylight, often afternoon | Native subterranean | Starting January to February in South Texas; statewide peak February to May |
| Larger, yellowish-brown swarmers circling lights after dark | Formosan subterranean | Late spring, about May into June |
| Swarmers in late summer, by day or night by species | Drywood | Late August to early September |
Texas A&M's Insects in the City gives the February to May statewide peak. The Formosan and drywood windows come from AgriLife's species bulletins. To learn more about each kind, see types of termites in San Antonio.
Inside the house or outside: what the location tells you #
Where the swarm happens matters more than how many insects you see.
- Indoors: AgriLife says swarmers that emerge inside usually mean an active infestation in the structure. Texas A&M's Insects in the City calls indoor swarmers a reliable signal of infestation.
- Outdoors: a swarm from a stump, fence or yard means termites live nearby and could move toward the house, but it does not by itself prove the house is infested.
- Around a porch light at night in May or June: worth a close look, since that pattern fits Formosan termites. See Formosan termites in San Antonio.
During a swarm: what to do and what to skip #
TDA's first piece of advice is not to panic: swarmers do not damage wood, and the colony's damage builds slowly.
Do:
- Collect several swarmers in a sealed plastic bag for the inspector.
- Note the room and the exact spot they came from, such as a window frame, baseboard or bathroom.
- Take photos of where they are coming out before they disperse.
Skip:
- Spraying the area or sealing the crack they came from before an inspection; TDA asks homeowners to leave the evidence for the inspector.
- Assuming the problem ended when the swarm did.
After the swarm: wings and what comes next #
Indoor swarmers usually die within about a day, according to the University of Kentucky's termite guide. What remains is often a scatter of wings on windowsills and floors. Those wings are the clue: bag a few, then schedule an inspection. The colony that produced them is still feeding even after the flight is over. Early clues are covered on signs of termites.
How Pest Trappers follows up after a swarm #
A Pest Trappers technician starts where the swarm came out and traces it back: the nearby wall, slab edge, plumbing openings, bath trap and foundation outside. Your saved samples help confirm which termite it is. The technician then explains what was found and the treatment options that fit, applies products only as their labels direct, and quotes the price after the inspection. Termite services are provided by Pest Trappers LLC (TPCL #0887549), licensed by TDA for termite control.
We serve San Antonio, Stone Oak and Cibolo, plus nearby towns. The termite fact sheet has more on how colonies live.