Flying termites in the house: what a swarm means, what to do tonight and when to call for a survey

A termite nest holds several castes: workers, which find the food and do the damage to timber; soldiers, which defend the nest; and a queen and king, which breed. When the nest is large enough and the weather is right, it produces a generation of winged termites whose task is to spread. They fly out together, pair off, drop their wings and look for somewhere damp, with wood or soil, to found a nest of their own.

Most never manage it. Birds and lizards catch them, they dry out, or they die without finding a suitable place. For a householder the useful information is the other half of the story: a mature nest somewhere close has just released its swarm.

Winged termites usually fly on warm, humid evenings, above all after the first rains of the season. In southern Vietnam the rainy season normally starts around May, so many households in Ho Chi Minh City meet the densest flights as the season changes. The exact timing varies with the species and with each year's weather.

A University of Florida (UF/IFAS) publication on the Asian subterranean termite, a species also present in Southeast Asia, records that it flies at dusk and is strongly attracted to light. That is why swarms gather at porch lights, street lamps and window sills, and why the insects get indoors through gaps around doors and through ventilation openings.

One flight lasts only a few evenings after rain, but flights can recur many times during the rainy season, because different nests and different species fly at different times. Height is no protection: the insects are drawn to light and can be carried upwards on the wind, so high-floor apartments see them too.

The Department of Entomology at the University of Kentucky gives three features that can be seen with the naked eye or a magnifying glass. A fourth clue is what lies on the floor the next morning.

No. Winged termites do not bite, do not sting and do not damage wood. The University of Kentucky notes that swarmers appearing indoors cause no immediate harm to the structure, usually live about a day and can be cleared with a broom or a vacuum cleaner. The nuisance is their number and the wings they drop through the rooms.

The harm to a house comes from the workers of the nest that sent the swarm out, which is why the next question matters more than this one.

Where the insects came from tells you more than how many there were. The same University of Kentucky publication states that finding winged termites emerging inside a house almost always indicates an infestation that needs treatment. A few that slipped in towards a lamp on one rainy night, and did not come again, usually belong to a nest outside.

In a flat on a high floor the test is the same: did they fly in from outside, or come out from somewhere inside the flat? Contact a termite service for a survey in any of these situations:

• Winged termites crawl out of a crack, a mortar joint, a door frame, skirting, a timber floor or a built-in wardrobe.
• Shed wings pile up at the same spot indoors, evening after evening.
• The house also has mud tubes (narrow runways of soil on walls and frames), timber that sounds hollow when tapped, or soil in wall cracks.
• They fly out of a planter, the base of a tree or a timber fence that stands against the house wall.
• The house has a garden or a lot of timber furniture, or has had termites before and was never checked again.

Tonight's work is to stop attracting them, clear up and keep the evidence. No insecticide is needed.

• Switch off most of the lights in the room and draw the curtains. If you need light, leave on a single lamp well away from the door.
• Close the windows and the balcony doors. If the windows have insect screens, check for gaps around the screen frames.
• On a loggia or porch, a shallow basin of water set under a lamp will collect the ones that fall into it.
• Gather the insects and the wings with a vacuum cleaner or a broom, seal them in a bag and put it outside. Keep food covered meanwhile.
• Keep a few termites or wings in a sealed bag or a small box, so that the species can be identified at a survey.
• Watch where they first appear and write it down: in from outside the window, or out of a wall crack, the foot of a cabinet, a timber floor or a power socket.

Killing the swarmers does nothing about the nest they came from, so none of the following is worth its risk.

• Do not spray insecticide freely in bedrooms or the kitchen. It has no effect on the nest and adds to the household's chemical exposure.
• Do not prise open a mud tube or chisel out the crack the termites came from before a survey has been done.
• Do not sign a contract in a hurry because you are worried. According to the University of Kentucky, termites damage wood fairly slowly, and taking more time to find out seldom adds much to the damage.
• Do not use fire or kerosene to burn them around lamps or curtains.

The next morning, once the wings are cleared, go back to the note you made of where the termites first appeared. A surveyor will want to know it, and so will you if the same thing happens the following evening.

A few days after the flight, look over the places where termites tend to found a nest or find a way into a house. A pair that has dropped its wings can settle indoors if it finds somewhere damp with wood or soil. Most fail, but it is worth clearing these places and keeping them dry.

If the swarm appears to start indoors, send photos, a short video and the place where you first saw the insects to 0968 726 135 on WhatsApp or Zalo; bookings are taken from 7:00 AM to 8:00 PM, seven days a week. UpClean surveys the home free of charge, checking the base of the walls, door frames, built-in cabinets, timber floors, ceilings and service shafts to find how far termites have got and where they enter. A plan and an all-inclusive quote follow in writing.

Treatment with product is carried out by UpClean's own pest-control technicians. Up specialists, UpClean's identity-verified and trained staff, protect the rooms, watch each working point and clean afterwards. The Up Report you receive by WhatsApp or Zalo after the visit is a record of the work with the schedule of follow-up checks. UpClean has declared its eligibility to provide pest-control services as required by regulation; the declaration and product information are available on request.

Enquiries, quotes, booking confirmations and the Up Report can all be in English. If you would like a specialist who speaks English in the home, say so when booking; if that cannot be arranged, you are told in advance and supported by phone or message. You also receive the specialist's name, photo and contact number before the visit. Many apartment buildings ask residents to register outside staff with building management, and UpClean sends those details so that you can.

Termite control

What the service includes, from the survey to the follow-up checks.

Termites in Saigon houses: the signs

Mud tubes, hollow timber and droppings, with a room-by-room check to do yourself.

Pest control

If the insects turn out to be flying ants or another pest.

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