When Do Termites Swarm & How Long Do Termites Swarm? Everything You Should Know
Swarming termites are not chewing your house while they fly. They are telling you a mature colony is close by, and that is the part worth acting on.
What a swarm actually means
Many homeowners believe that termite swarms will damage their property, but that is not exactly true. Termites do serious structural damage across the country every year, and they do not do that damage while they are swarming. Swarming is simply part of the regular termite life cycle.
If you see swarming termites, though, it is normal to be concerned. A swarm points to a nearby colony that could be eating into your home. Below is what the different termite types look like, how a colony grows, when each subgroup swarms, and what to do when a swarm shows up.
Common types of termites
Termites have a destructive appetite for wood, which makes them a dangerous nuisance. Three groups account for nearly every home infestation.
Dampwood termites
Dampwood termites are large compared to other common termite types. As their name implies, they live in damp and often decaying wood. They thrive on moisture and do best in high humidity environments, such as the Pacific coast. Their colonies are typically small, though they can grow to substantial sizes in the right environment. Unless your home’s wood has a significant moisture content, dampwood termites probably are not a cause for concern. Most home and property owners have trouble with drywood or subterranean termites instead.
Drywood termites
Drywood termites require far less moisture than their dampwood counterparts. Still, they also prefer to nest in wood rather than soil. Drywood termites can cause significant structural damage to homes and buildings, and their colonies usually consist of a few thousand termites.
Subterranean termites
Subterranean termites are the most destructive to homes and other wood structures, because they usually have large underground colonies to support. They do not nest in wood like other types. Instead they build their homes in the soil, then use mud tubes to travel from the nest to wood-based food sources. Usually those mud tubes are visible around the foundation of your home. If you see them, you know you have a termite problem.
The termite life cycle
To understand when termites swarm, and why, it helps to know how the colony is organized.
Queen termite
Termite colonies begin with the queen. Queens are large and often pale, yellow-brown. They spend their days laying eggs, usually several thousand throughout their lives. The eggs hatch as nymphs and then go through a series of molts until they become one of the four adult termite types.
Worker termites
Worker termites are white or even transparent. They gather food and care for termite eggs and nymphs. Subterranean worker termites also build the mud tubes that attach the colony’s nest to its nearby food source.
Soldier termites
Soldier termites are large and often dark-colored, either brown or black. They have massive mandibles that they use to crush potential nest or tube invaders.
Primary and supplementary reproductive termites
The primary and supplementary reproductive termites are responsible for mating, laying eggs, and developing termite swarms. Initially the queen does the egg-laying, but as she matures she produces supplemental egg producers. Once supplemental egg producers are present, a colony grows rapidly. Eventually these termites establish new colonies. When that time comes they gain wings, after which they swarm, mate, and find new homes.
We break the stages down further in our guide to the termite life cycle.
Alates, mating flights, and what you see at the window
Alates, or winged reproductive termites, are responsible for the swarms homeowners sometimes see. Here is why and when they happen.
What is a termite swarm?
Only the winged reproductive termites can create a termite swarm. They do this when their colony size and the local weather align, making it possible for a swarm to form. Under the right conditions the alates begin to emerge, take to the air, and form mating pairs. Homeowners usually spot subterranean termite swarmers near windows or light fixtures, because these structure-eating pests are attracted to light. The swarms can last a few days or up to a few weeks, depending on the colony and the local weather.
Why do termites swarm?
Termites swarm to establish new colonies, which means they only swarm once their former colony has reached a significant size. The weather conditions must also be right. For most species this happens once per year. When conditions line up, swarmers take off from their nests and pair up, one male to one female. Each pair may only be in the air for a few seconds, but the swarm as a whole usually continues for several days or a few weeks.
What happens after the swarm?
After they swarm and pair, couples shed their wings, mate, and find a nesting place where they establish a new colony. The number of swarmers varies significantly based on colony size and termite subgroup. If there are multiple colonies in an area, they will likely swarm at the same time, and the different colonies may also exchange alates.
When do termites swarm?
Termites swarm at different times depending on their subgroup and where the nest sits. Usually it is during or just after the rainy season, in spring or summer, on a day with minimal wind.
Warm, humid weather is ideal for termite swarmers. Here are the swarming windows for common termite subgroups.
- Arid-land subterranean termite
Usually between January and March. At high elevations they can swarm as late as July.
- Eastern subterranean termite
Spring or early summer.
- Formosan termite
Late spring to early summer.
- Dark southeastern subterranean termite
Summer.
- Western drywood termite
Late summer to early fall.
For the Texas calendar specifically, see our breakdown of termite season in Texas.
Getting rid of termite swarms
Termites do not damage structures while they swarm, but their presence points to a well-established colony nearby.
In other words, if you see a termite swarm near your home, you could already have a full-blown termite infestation. There are steps you can take to make swarms, infestations, and the damage that follows far less likely.
- Keep fences and any other wooden structures in good condition.
- Make sure you do not have any rotting wood on your property.
- Remove dead trees, logs, and bushes from around your property.
- On new construction, use treated wood that contains chemicals to repel termites.
- During construction or renovation, add metal shields along the building foundations. These act as a barrier against termite colonies.
If you see a swarm or notice any sign of termite damage near your property, call for professional termite control. If the swarm is inside your home, the house itself needs to be treated, so call for professional help right away.
How long do termites swarm after treatment?
Sometimes termites still swarm after a treatment goes down. Termite treatments vary in effectiveness depending on the products and the application method, and it can take several weeks for a treatment to eliminate a colony.
Many treatments work on the moisture in the wood of your home or building. Lower moisture content leads to termite dehydration and then death. In other words, treatments cannot deliver an instant end to termites. They take a little time, and alates are more resilient to typical termite treatments than the workers are, so seeing swarmers for a while after treatment does not mean the treatment failed.
If swarmers are still appearing weeks later, tell the company that treated the property so they can re-inspect and confirm the colony is dying off. You can also review the signs of termites to check whether the activity you are seeing is new.
A swarm near the house means a colony near the house
Swarming termites are the easiest termite sign to spot and the easiest one to shrug off. If you have seen them at your windows or found shed wings on a sill, have the property inspected.
Keep reading
Signs of Termites & What To Do About Them
Termite infestation is a common problem in the US, with more than 600,000 homes affected yearly. Here are the signs of termites to watch out for.
Read articleTermitesAnts vs. Termites: How To Tell the Difference
They look similar, but ants and termites do different degrees of damage. Learn how to tell the two apart, point by point.
Read articleTermitesTermite Season in Texas
When termites swarm in Texas, and what homeowners should do to protect their biggest investment.
Read articleThink you have termites? Talk to us.
Tell us what you are seeing and we will schedule a termite inspection for your property.