Most termites are active around the clock, but the ones you’re likely to see with your own eyes do tend to appear at night. The winged termites that swarm out to start new colonies often launch after dark, especially the most destructive species in the U.S. The worker termites chewing through wood, on the other hand, never stop, day or night. They just do it hidden from view.
Why Workers Stay Hidden 24/7
Worker termites, the ones actually causing structural damage, don’t follow a day-night schedule. They forage and feed continuously. But you’ll almost never see them in the open because their bodies aren’t built for exposure. They’re blind, soft-bodied insects with thin exoskeletons that lose moisture rapidly in open air. Even brief exposure can be fatal through dehydration.
To stay protected, workers travel through enclosed pathways: underground tunnels, mud tubes built along foundation walls, or galleries carved inside the wood itself. They navigate by following surfaces like wall studs, never venturing into light or open spaces. These mud tubes also shield them from predators like ants. So while workers are technically active at night, they’re equally active during the day. You just can’t see either way unless you break open an infested piece of wood or spot a mud tube on your foundation.
Swarming Termites and Nighttime Flights
The termites people actually notice at night are swarmers, also called alates. These are winged reproductive termites that leave an established colony to mate and start new ones. Unlike workers, swarmers have eyes and harder bodies designed for a brief life in the open air. Their flight is the one moment in a termite colony’s life cycle that happens out in the world where you can witness it.
Formosan subterranean termites, one of the most aggressive and damaging species in the southern U.S., swarm at night in late May and early June. They’re strongly attracted to lights, which is why homeowners often find them clustering around porch lights, streetlights, and illuminated windows. A typical swarm lasts only about 30 to 40 minutes, so by the time you notice them, the event may already be winding down.
Not all species swarm at night, though. Most native subterranean termites swarm during daytime hours in spring and summer, typically on a warm day with calm winds after a rainfall. Drywood termites tend to swarm later in the year, from August through November. The timing depends on species, geography, and weather conditions, but Formosan termites are by far the most common nighttime swarmers homeowners encounter.
What Nighttime Swarms Look Like
If Formosan termites are swarming near your home at night, you’ll see a cloud of small winged insects buzzing around any light source. They’re about half an inch long, pale yellowish-brown, with two pairs of wings that are roughly equal in length. After landing, they shed their wings almost immediately. The next morning, you may find piles of tiny, translucent discarded wings on windowsills, near doors, or beneath outdoor light fixtures.
Finding a few dozen swarmers inside your home during swarm season doesn’t necessarily mean your house is infested. Formosan swarmers from nearby trees or neighboring colonies can accidentally enter buildings through open windows or gaps around doors, drawn by indoor lighting. Finding hundreds of swarmers inside, however, is a strong indicator of an active infestation in or very close to the structure, regardless of any past treatment the building has received.
How Outdoor Lighting Draws Them In
Light color matters more than most people realize. Research on insect attraction to artificial lighting has found that blue and ultraviolet wavelengths draw in far more flying insects than warmer colors. Cool-white LED bulbs and standard fluorescent lights produce significant amounts of blue-spectrum light, which acts like a beacon for swarming termites and other nighttime insects.
Yellow or amber-filtered LED lights attract substantially fewer flying insects. If you live in an area with Formosan termite activity, switching your porch and exterior lights to warm amber LEDs during swarm season (late spring) can make a real difference. Dimmer settings help too. The simplest option is turning off unnecessary outdoor lights entirely on warm, humid evenings after rainfall, which are exactly the conditions that trigger swarms. If a light needs to stay on, amber is always better than white.
It’s also worth closing windows and doors on those evenings, or making sure screens are intact. Swarmers that get inside are mostly a nuisance since they die within hours without establishing a colony in most cases. But large numbers getting in can indicate a nearby colony worth investigating.
Signs of Activity You Can Check at Any Hour
Since the termites doing real damage work invisibly around the clock, nighttime isn’t actually the best time to look for evidence of a problem. The signs are static and visible whenever you check. Mud tubes running up foundation walls, along pipes, or in crawl spaces are the most reliable indicator of subterranean termite activity. These pencil-width tubes are made of soil and saliva and can appear on concrete, brick, or wood surfaces.
Other signs include wood that sounds hollow when tapped, bubbling or peeling paint that resembles water damage, and small holes in drywall. Drywood termites leave behind tiny pellets of frass (fecal matter) that look like fine sawdust or sand, often accumulating in small piles below infested wood. These clues are present day and night because the colony never rests.