Termite Swarm Season in Dallas: What a Swarm Means and What to Do

When do termites swarm in Dallas?

Eastern subterranean termites swarm in Dallas mostly from late February through May, in daylight, typically on a warm, humid day right after a rain. Formosan termites, where present, swarm later and at dusk, roughly late April through June. A few stray swarms can show up outside those windows, but spring is the main event.

The trigger is weather, not the calendar. A colony holds its winged termites until conditions suit them: warm air, damp soil and calm conditions. In southwest Dallas that often means the first warm afternoon after a February or March storm, when the clay is soaked and the temperature jumps.

The flight itself is brief. Swarmers pour out of a crack, a wall void or a gap by a window, flutter toward the light, drop their wings and pair off. Most die soon after, but their shed wings stay behind on windowsills and floors as the clue most people notice first.

Our southwest Dallas pest calendar shows where swarm season sits among the other spring pests, from fire ants to paper wasps.

How can you tell termite swarmers from flying ants?

Look at the antennae, waist and wings. Termite swarmers have straight, beaded antennae, a thick waist with no pinch, and four wings of equal length that snap off easily. Flying ants have bent antennae, a narrow pinched waist, and front wings longer than the back pair. A clear phone photo is often enough to tell.

Fire ants and other ants also send out winged swarms after spring rains, so timing alone will not settle it. Catch a few swarmers in a zip-top bag or on clear tape and put them in the freezer. That sample, plus a photo of any wings left on the sill, helps a technician identify them quickly.

What does a termite swarm inside the house mean?

Swarmers inside the house almost always mean a mature colony is feeding in or under the structure, close to where they came out. A colony usually takes several years to start producing swarmers, so the termites have likely been there a while. Outdoor swarms from a stump, fence or woodpile may not involve the house at all.

Swarmers do not chew their way out through solid walls. They leave through existing gaps: a crack in the slab under carpet, a bathtub drain opening, a window frame, or the joint where a door frame meets the floor. Where they emerge is a strong clue to where the colony is working.

Stay calm. Termites cause damage slowly, over months and years, so you have time to get an inspection and a clear plan. What you should not do is wait until next spring to see whether it happens again.

A swarm outside still deserves a look. If it boils out of an old landscape tie or a stump by the back fence, that colony may be foraging under your slab as well.

Why are Oak Cliff and Redbird homes open to termites?

Age, foundations and clay. Pre-war bungalows and Tudors in Winnetka Heights and Kessler often sit on piers with crawlspaces that give termites many routes to wood. The 1950s–70s brick ranches in Redbird and Wynnewood sit on slabs, where Blackland clay movement cracks concrete and opens gaps around plumbing.

Houston Black clay and its relatives swell when wet and shrink when dry. In August the yard splits open, and in May it is saturated. That seasonal movement stresses slabs and shifts piers, and every new crack is a possible route from the soil to the framing.

Pier-and-beam houses carry their own risks: wood sills close to the soil, damp crawlspaces, and skirting or porches built right against the dirt. Slab homes hide termites better. Colonies often travel up through bath traps, expansion joints and the space behind brick veneer, out of sight until a swarm or a soft baseboard gives them away.

Moisture multiplies everything. Dripping outdoor faucets, AC condensate lines draining against the foundation and flower beds watered every evening keep the soil next to the house damp all summer, which is exactly what a foraging colony looks for.

Are Formosan termites in Dallas County?

Formosan termites have been reported in Dallas County, but they are not the termite most homes deal with. First found in Texas in 1956 near the Houston Ship Channel, they turned up in North Texas cities such as Aledo, Grapevine, Flower Mound and Rockwall from the 1990s, probably carried in old railroad ties.

Formosans behave differently from the native species. Their swarms come at dusk, roughly late April through June, and the swarmers crowd around porch lights and streetlights. They are larger and paler than native swarmers, a yellowish brown, and often fly in big numbers. Their colonies can grow very large, which is part of why treatment for a confirmed case costs more.

Railroad ties used for retaining walls and landscape borders are the suspected way they reached North Texas, and a later find came from a neighborhood in Wylie, in Collin County. If your yard has old ties holding up a bed or a slope, point them out during an inspection.

No one can say a particular street has Formosans without an inspection. If one confirms them, Formosan termite treatment runs $1,500–$4,500 and is quoted after that inspection.

What should you do in the first day after a swarm?

Collect a sample, clean up, and call for an inspection. Vacuum the swarmers, save a few in a sealed bag, photograph the spot where they came out, and do not spray the area or seal the crack. Leaving the exit point alone helps a technician trace the colony and plan the right treatment.

A termite inspection covers the foundation, the crawlspace or slab openings, the attic, the garage and the yard, looking for mud tubes, damaged wood and moisture problems. You can reach someone at (855) 974-4733 at any hour, and most calls are scheduled the same day when a technician is available.

While you wait, look for other signs: pencil-width mud tubes running up the foundation or piers, baseboards that sound hollow when tapped, and paint that bubbles or blisters. Doors that suddenly stick can mean termites, but on clay soil they often point to foundation movement instead, so let the inspection sort that out.

• Vacuum up swarmers and wings; they do not bite and will not damage anything.
• Save several swarmers in a zip-top bag or taped to an index card.
• Photograph where they emerged: a baseboard, window, bath trap or slab crack.
• Skip store-bought sprays and foggers, which kill swarmers but leave the colony untouched.
• Leave the exit point uncaulked until after the inspection.
• Note the date, time of day and weather, which helps separate subterranean from Formosan swarms.
• Book a termite inspection, which runs free to $150 in Dallas County.

How are termites treated, and what does it cost in Dallas County?

The two main options are a liquid termiticide in the soil around the foundation and a bait system of stations set around the house. Liquid treatment on a typical slab home runs $1,200–$3,000. Bait systems cost $1,200–$2,800 to install plus $300–$550 a year to monitor. Pier-and-beam homes are quoted after inspection.

Liquid treatment places a continuous zone of termiticide in the soil along the foundation and at plumbing and slab penetrations. On a slab, that can mean drilling through a patio or garage floor and patching the holes. Bait stations go into the ground around the house; termites feed on the bait, carry it back to the colony, and the stations are checked on a schedule.

The right choice depends on the foundation, how far the activity has spread, and how you feel about yearly monitoring. Your technician explains the trade-offs, follows the product label, and leaves a written service report. More detail is on our termite control page.

How can you lower the odds of a swarm next spring?

Cut moisture and wood contact around the foundation, then keep watching. Fix leaks, route AC condensate and downspouts away from the slab, pull mulch back from the walls, store firewood off the ground, and remove old stumps and railroad ties. A yearly winter inspection catches activity before the next swarm season starts.

Grading matters on clay. Water that ponds against the slab after a May storm keeps the soil wet for days, so the ground should slope away from the house. Some homeowners water near the foundation during summer drought to limit clay movement; if you do, keep it even and avoid soaking the soil right against the walls.

January and February are a good time for a check. The technician looks for mud tubes on the foundation and piers, soft or damaged wood, and damp spots, so you have a plan in hand before the first warm, rainy afternoon. Building new? A pre-construction termite treatment on the new slab runs $400–$1,200.