In Southeast Texas, native (Eastern) subterranean termites swarm in daylight on warm days from late winter through spring, often after rain. Formosan subterranean termites swarm at dusk in late spring, typically late May into June, and fly toward lights. Swarmers indoors mean an active colony nearby: save a few, don't spray, and book an inspection.
Key takeaways
- Native subterranean termites (Reticulitermes species) swarm during the day, mostly February through May in Texas, often on a warm morning after rain.
- Formosan subterranean termites (Coptotermes formosanus) swarm from dusk toward midnight in late spring and are strongly attracted to lights.
- Termite swarmers have straight antennae, a thick waist and four wings of equal length; flying ants have elbowed antennae, a pinched waist and longer front wings.
- Swarmers that emerge indoors die quickly because they can't reach soil, but they signal an active colony in or under the structure.
- In Montgomery County, liquid treatment typically costs $1,200–$3,000, while a bait system costs $1,200–$2,500 to install plus $300–$500 a year to monitor.
- A termite report for a Texas real estate transaction must be made on the Texas Department of Agriculture's official Wood Destroying Insect Report form.
When do termites swarm in Southeast Texas?
Native subterranean termites usually swarm between February and May in Southeast Texas, in daylight, often on a warm, humid morning after rain. Formosan subterranean termites swarm later, typically from late May into June, beginning at dusk and continuing into the night. Swarms can occur outside these windows, especially from colonies under heated slabs.
A swarm is how a mature colony reproduces. Winged males and females (alates) leave together, pair off, drop their wings and try to start a new colony in moist soil. Most fail, but a swarm tells you a colony, usually several years old, has been feeding nearby.
Formosan termites were first found in Texas near the Houston Ship Channel in 1956 and have since spread to dozens of counties, including much of the Houston region. Their colonies are far larger than native colonies, which is why a dusk swarm around a porch light deserves quick attention.
| Feature | Eastern / native subterranean | Formosan subterranean |
|---|---|---|
| Scientific name | Reticulitermes species, including R. flavipes | Coptotermes formosanus |
| Typical swarm months | February to May | Late May into June |
| Time of day | Daytime, often morning to midday | Dusk toward midnight |
| Weather trigger | Warm day after rain | Warm, humid, still evenings |
| Swarmer color and size | Dark brown to black, about 3/8 inch | Yellowish-brown, about 1/2 inch, hairy wings |
| Attracted to lights? | Not strongly | Yes, strongly |
| Colony size and damage | Smaller colonies, slower damage | Very large colonies, faster damage; can nest above ground in walls |
How can you tell termite swarmers from flying ants?
Look at the waist, antennae and wings. Termite swarmers have a thick, straight waist, straight beaded antennae and four wings of equal length that break off easily. Flying ants have a pinched waist, elbowed antennae and front wings longer than the back wings. A pile of identical shed wings on a windowsill usually means termites.
If you're not sure, collect a few insects and let a professional look at them. Texas A&M suggests keeping specimens in a small crush-proof container with rubbing alcohol and noting the date and the room where you found them. If they turn out to be ants, general pest control is a different and much cheaper fix than termite work.
| Feature | Termite swarmer | Flying ant |
|---|---|---|
| Waist | Broad, no pinch between body sections | Narrow, pinched 'wasp waist' |
| Antennae | Straight, like a string of beads | Bent at an elbow |
| Wings | Four, equal length, many fine veins, extend well past the body | Four, front pair longer than back pair, few veins |
| Shed wings | Drop off easily; piles on sills are common | Usually stay attached longer |
| Color | Dark brown to black (native) or yellowish-brown (Formosan) | Black, red or brown, depending on species |
| When seen | Native in spring daytime; Formosan at dusk in late spring | Many species, often in summer and after rain |
What should you do when termites swarm inside your house?
Stay calm, collect a few swarmers, note where they came from, and arrange a termite inspection within the next few days. Swarmers don't eat wood or survive long indoors, so you have time to get a proper inspection and quote. Vacuum the rest once you have saved samples, and leave any mud tubes intact for the inspector.
Swarmers usually emerge near the point where the colony has reached the structure: plumbing penetrations under bathtubs, expansion joints, door frames, windowsills on the warm side of the house or cracks in a slab. That location is the most useful clue you can give a technician.
- Save 5–10 swarmers in a jar or zip bag with rubbing alcohol.
- Note the room, the time of day and the exact spot: window, tub, light fixture or baseboard crack.
- Photograph any mud tubes, shed wings or bubbling paint before you clean up.
- Vacuum the remaining swarmers and wings.
- Book an inspection; termite damage builds slowly, so you usually have days to weeks, not hours, to decide on treatment.
What should you not do during a termite swarm?
Don't spray store-bought insecticide on swarmers or mud tubes, don't tear out drywall, and don't sign an expensive contract on the spot. Spraying kills only the swarmers and can hide the evidence an inspector needs to find the entry point. Swarmers are a symptom; the colony in the soil is the real target.
- Don't break open mud tubes; inspectors use them to judge whether activity is current.
- Don't leave mulch or pine straw piled against the slab, or firewood stacked next to the house.
- Don't assume a newer home is safe; slab-on-grade houses still have plumbing and expansion-joint gaps termites use.
- Don't settle for a single estimate if the price or the sales pressure feels off.
Liquid termite treatment or bait system: which is better?
Both work when done properly. A liquid treatment applies a non-repellent termiticide to the soil around and under the foundation, usually in one visit, typically $1,200–$3,000 in Montgomery County. A bait system costs $1,200–$2,500 to install plus $300–$500 a year to monitor, avoids most drilling, and works more slowly by eliminating the colony.
Neither method is right for every house; the choice depends on the construction, how active the infestation is and your budget. Many Magnolia homes on wooded lots have patios, additions and flatwork poured against the slab, which raises the drilling cost of a liquid treatment and can tip the decision toward bait.
Either way, ask for a written graph of the treatment and a service report listing the product, where it went and how much was used. That record matters when you sell the house, and termite control visits from Magnolia Pest Control include it. For how these prices compare with other services, see our pest control cost guide.
| Factor | Liquid treatment | Bait system |
|---|---|---|
| Typical cost | $1,200–$3,000 per home | $1,200–$2,500 to install, then $300–$500 a year |
| How it works | Treated soil zone that termites contact as they tunnel through | Termites feed on bait and share it, slowly eliminating the colony |
| Speed | Protection starts once the soil is treated | Often weeks to months to eliminate a colony |
| Drilling | Often needed through patios, garage slabs and walks touching the house | Usually none; stations go in the soil around the house |
| Ongoing care | Periodic re-inspection recommended | Yearly monitoring is part of the system |
| Good fit | Active infestations needing fast control | Homes near wells or water features, or owners who want minimal drilling |
What does a termite inspector check?
An inspector walks the outside and inside of the house looking for mud tubes, damaged or blistered wood, shed wings and moisture problems. They check the slab edge, plumbing penetrations, expansion joints, door frames, the garage, the attic and any crawl space, and note conducive conditions like wood-to-soil contact, mulch against the slab and leaking AC lines.
The inspector also looks for anything that hides termites. Brick or stone veneer that extends below the soil line, rigid foam insulation on the slab edge, and stucco that runs into the ground can let termites travel unseen. Probing or tapping baseboards and door trim finds hollow wood that looks fine on the surface.
A termite inspection in Montgomery County typically costs from free to $125. If you get a sales pitch before the inspector has looked in the garage, the attic and around the full slab, ask for the inspection to be finished first.
Do you need a WDI report to sell a house in Texas?
Texas doesn't require a termite report for every home sale, but buyers and some loan programs ask for one. When a report is issued for a real estate transaction, it must be made on the Texas Department of Agriculture's official Wood Destroying Insect Report form. In Montgomery County, a WDI report typically costs $75–$150.
The official report records visible evidence of termites, carpenter ants, carpenter bees and wood-boring beetles, plus conditions that invite them. It describes what the inspector could see on the day, so stored boxes, finished walls and inaccessible areas are noted as limits.
If the report finds active termites, buyer and seller usually negotiate treatment before closing. Having recent service records and a treatment graph on hand makes that conversation much easier.
Frequently asked questions
Do termite swarmers bite or damage furniture?
No. Swarmers don't bite people and don't eat wood; their only job is to mate and start new colonies. The damage comes from worker termites that stay hidden in soil, walls and mud tubes.
If the swarmers died on my windowsill, is the problem over?
No. Swarmers die quickly indoors, but the colony that produced them is still feeding. A swarm from inside usually means termites have reached the structure, so an inspection is the next step even if you see no more insects.
Can I treat termites myself?
Over-the-counter products can kill termites you can see, but protecting a home usually means trenching and drilling with professional termiticides or installing monitored bait stations. Treatment also needs a record for a future sale, so most homeowners are better served by an inspection and a written quote.
Why are Formosan termites considered worse than native termites?
Formosan colonies can be far larger than native colonies, so they consume wood faster, and they can build nests inside walls without returning to the soil when moisture is available. Their dusk swarms toward lights in late spring are often the first sign.
Does homeowners insurance cover termite damage?
Usually not. Most standard homeowners policies treat termite damage as a preventable maintenance issue and exclude it, though you should check your own policy. That's a strong reason to act on swarmers quickly.
Sources
- Texas A&M Urban and Structural Entomology Program – Formosan Subterranean Termites
- Texas A&M Urban and Structural Entomology Program – Native Subterranean Termites
- Texas A&M AgriLife Extension (Insects in the City) – Swarming Insects Indoors
- Texas A&M AgriLife Extension (Insects in the City) – Frequently Asked Questions About Subterranean Termite Control
- Cornell Law School LII – 4 Tex. Admin. Code § 7.176, Real Estate Transaction Inspection Reports
This guide is general information for Montgomery County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.