Why Are Formosan Termites So Concerning? 8 Reasons

Formosan termites are so concerning because they combine everything that makes termites expensive: colonies of millions, a long foraging range, fast feeding, the ability to nest inside walls and trees without touching the ground, and a habit of chewing through materials other than wood. Texas A&M AgriLife Extension calls them one of the most aggressive and economically devastating termite species in the world.

South Florida has extra reasons to pay attention. The Formosan subterranean termite is established throughout the state’s cities, and in Miami-Dade and Broward it now shares territory, and even mates, with the invasive Asian subterranean termite. Here are the eight reasons scientists and pest professionals take this “super termite” so seriously.

Where Formosan Termites Came From

Coptotermes formosanus is native to Taiwan and southern China. It reached Hawaii by the late 1800s and the continental United States later, with early records from New Orleans, Charleston and Hallandale, Florida. UF/IFAS says its spread is most likely the result of human transport, such as moving infested wood, and it now ranges from Hawaii across the Southeast.

In Florida it is found statewide, mainly in densely populated urban areas. For a full species profile, see what Formosan termites are.

Reason 1: Colonies of Several Million Termites

Formosan termites build some of the largest colonies of any termite. UF/IFAS reports underground colonies of several million individuals, and Texas A&M AgriLife Extension says Formosan colonies are at least four times as large as those of native subterranean termites. A new colony may grow to more than a million termites within five years.

Colonies are also long-lived. UF/IFAS termite researcher Nan-Yao Su has noted that a colony can live up to 20 years. That means a colony that settles near your home can keep feeding and swarming for a very long time.

Reason 2: They Eat Faster and More Aggressively

More termites means more mouths, but Formosan termites also feed more aggressively. Texas A&M AgriLife Extension notes they consume a variety of woods faster than native subterranean termites, and that they eat both the softer early-season wood and the denser late-season wood in each growth ring, which makes them more destructive than other species.

Their soldiers are part of the story. UF/IFAS says Formosan colonies contain a higher share of soldiers, about 10-15% of the colony, and Texas A&M describes them as more aggressive than native soldiers, which helps the colony defend its foraging territory.

Reason 3: A Huge Foraging Range

A single colony does not stay in one yard. UF/IFAS has found Formosan termites foraging up to about 100 meters (328 feet) in the field and up to 300 meters in laboratory studies. One colony can therefore reach several homes, trees and fences at the same time.

Here is how they compare with Florida’s most common native subterranean termite:

Sources: UF/IFAS EDIS IN278 and IN369. Learn more about the native species on our eastern subterranean termite page.

Reason 4: They Chew Through More Than Wood

Wood is their food, but it is not the only thing in their way. According to Texas A&M AgriLife Extension, Formosan termites may chew through non-cellulose materials such as asphalt, plaster, rubber and plastic while searching for food, and their damage can lead to electrical shorts that start fires.

They also exploit the smallest openings. Like other subterranean termites, they do not eat concrete, but they use cracks, expansion joints and gaps around plumbing to reach the wood above. Our guide to how Formosan termites enter buildings maps those entry points.

Reason 5: Aerial Nests That Survive Without the Soil

Most subterranean termites must return to the soil for moisture. Formosan termites can build carton nest, a blend of soil, chewed wood, saliva and feces, inside wall voids. Texas A&M AgriLife Extension explains that when moisture is available, this carton forms an aerial nest in the wall, and if the colony is separated from its underground nest, the aerial nest can survive and keep damaging the structure.

In practice, that means a roof leak, a plumbing leak or chronic condensation can give Formosan termites a base inside your building, sometimes well above the ground floor. Treating only the soil may not be enough when an aerial colony is involved.

Reason 6: They Hollow Out Living Trees

Formosan termites attack trees too. Texas A&M AgriLife Extension says they have been known to attack more than 50 tree species. UF/IFAS explains that they usually feed on the dead wood at the center of the trunk and hollow out the tree from the inside.

The tree may look healthy, but it loses strength. UF/IFAS termite scientist Thomas Chouvenc warns that trees weakened by termites are more likely to fall during storms, and notes that after a storm, trees often end up on roofs and cars. In hurricane country, that turns a termite problem into a safety and property risk. After a storm, read our guide to termites after the storm.

Reason 7: The Economic Damage Is Enormous

All this adds up. UF/IFAS estimates that the annual economic impact of the Formosan subterranean termite alone in the United States is likely more than $4 billion, as part of an estimated $30 billion-plus yearly cost for all subterranean termites.

For homeowners, the concern is that the damage is hidden. Formosan termites work inside walls, floors and trees, so damage can be extensive before anyone sees it.

Reason 8: They Are Hybridizing With Asian Subterranean Termites

The newest concern is unique to South Florida. In 2015, UF/IFAS scientists reported that Formosan and Asian subterranean termites swarm at overlapping times here and that male Asian termites prefer to mate with Formosan females. In lab studies, hybrid colonies developed about twice as fast as either parent species.

In 2025, UF/IFAS confirmed that hybrids are established in the wild: a hybrid colony was found in a tree in a Fort Lauderdale city park in October 2024, and hybrid swarms have been recorded every year since 2021. The lead researcher estimated the colony had been there for more than five years and that many more may exist across urban South Florida. Learn more about the other parent species on our Asian subterranean termite page.

When Formosan Termites Are Most Noticeable

Formosan termites typically swarm from early April to late June, shortly after sunset, with peak activity in May. The flights can contain tens of thousands of swarmers, and they gather around porch lights and lit windows. Large numbers of swarmers indoors usually point to a structural infestation. See the full calendar in when termite swarming season starts.

How to Protect Your Home From Formosan Termites

Because of their size and range, UF/IFAS says control of Formosan termites requires professional pest control services, and over-the-counter products are unlikely to work. What you can do is make your home less inviting and easier to inspect:

• Fix leaks and keep the foundation dry with good drainage and well-aimed sprinklers.
• Keep mulch thin and away from the slab, and keep wood off the soil.
• Turn off unneeded outdoor lights on spring evenings to draw fewer swarmers.
• Have trees near the house checked for mud tubes and hollow trunks.
• Schedule an annual termite inspection.

Our step-by-step plan on how to prevent Formosan termite infestations goes into each step in detail.

How Professionals Control Formosan Termites

UF/IFAS describes two proven approaches. Liquid termiticides applied to the soil protect the area near the structure but may not eliminate the colony. Termite baits are carried back to the nest and can eliminate an entire colony, a process that takes about three months because the termites die as they fail to molt.

Toro’s termite control service starts with a free inspection to confirm the species and how far it has spread. For Formosan and other subterranean termites, Toro installs the Sentricon baiting system around the property, with no drilling into the slab and no trenches. The bait is designed to eliminate the colony, including the queen, and the stations stay in place for year-round protection against new colonies. Toro has protected South Florida since 1969, and if the bugs come back, so will Toro, at no additional cost to you.

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Frequently Asked Questions

Educational content. This article is for general information about pests in South Florida and is not medical, legal or professional advice. If you have a bite, sting or allergic reaction, contact your doctor; in an emergency, call 911. Pest problems vary from home to home, so a licensed professional should inspect before treatment. When using any pesticide, always read and follow the product label.

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