Mosquitoes are thriving in Tampa Bay. Inside the effort to stave them off.

CLEARWATER — The girls were squawking.

One bawk turned into a chorus of squeals.

“I’ve never seen them do this before,” said Austin Deal, an entomologist assistant with Pinellas County Mosquito Control. When he nestled a hen under his arm just a few minutes earlier, she barely made a peep.

“We’ve been in here too long without giving them treats,” he said.

The ladies — dozens of Red Star hens shuffling around the enclosed chicken coop at the main Pinellas County Mosquito Control lot — were purchased months ago as chicks, chosen for their (typically) docile nature.

Eventually, each hen will find her way to one of eight coops across the county, where each Monday, employees will draw about a milliliter of blood.

The chickens will find themselves unwitting recruits in the war on mosquitoes. If one of three diseases shows up in their blood, officials know that the disease is present in nearby mosquitoes.

Chickens are just one strand in the large web of monitoring mosquito populations and the viruses they may carry. Across Florida, more than 60 mosquito control programs have their own methods and capabilities to combat the pests.

While mosquitoes are active year-round in Florida, it’s now — when the hot, wet weather really kicks in — that they thrive.

And as climate change prolongs warm weather and brings more intense storms, Florida’s environment will only become more hospitable to the little suckers.

To get a closer look at the conflict, the Tampa Bay Times toured mosquito control centers across the region.

Behind the curtain of mosquito control

Tucked behind a chain-link fence, the Pinellas County Mosquito Control resides near an industrial park in Clearwater.

It’s a complex where buildings, including a hangar that houses a helicopter, are surrounded by Florida-friendly plants, a beehive, mosquito-eating fish in buckets and, of course, the chicken coop.

Workers often head into the field, where they tend to the chickens across the county. They place mosquito traps that simulate bodily emissions to draw mosquitoes, such as dry ice to imitate human breath and a device that stinks like sweat.

“There’s a lot of technology that’s come a long way, but the true old way is still the best way,” said Jason Stuck, a 27-year mosquito control employee. “You get out there with your boots … and go find them.”

Mosquitoes kill more people than any other animal on the planet, according to Gordon Patterson, a professor at the Florida Institute of Technology and author of “The Mosquito Wars.”

Centuries ago, Florida, particularly along the coasts, was deemed nearly uninhabitable because of the insects. The state was plagued by epidemics of dengue and yellow fever.

Dozens of mosquito control districts now exist across Florida, including in Pinellas, Hillsborough and Pasco. While operations are similar, they aren’t identical. For example, Pinellas and Hillsborough’s mosquito control are run within the county, while Pasco’s is an independent special district financed by its own property tax.

It means mosquito control methods and budgets can vary widely across a state where about 90 mosquito species live.

Not all mosquitoes bite us

In Pinellas, workers return daily with the traps and spread the dead insects on a piece of paper. With tweezers, they parse through what resembles a mound of fake eyelashes, counting and documenting the mosquitoes by hand.

Only some mosquitoes carry diseases. In Pinellas County, there are 40 species of mosquitoes but just 17 that officials say pose a serious concern.

Mosquito control can calculate how many mosquitoes land on a person in a minute. When it reaches around 10, then there’s likely a problem, said Alissa Berro, director of Pinellas County Vegetation Management and Mosquito Control.

Some staff are so accustomed to bites that they’ve developed an immunity to mosquito saliva, which can cause itchy, splotchy marks, said Caroline Scott, a senior environmental specialist for Pinellas County.

But not all mosquitoes bite people. Some take their “blood meals” (the unfortunate way researchers describe how mosquitoes feed) from birds, reptiles or even leeches, Berro said. The bloodsuckers are all female.

Trapping and identification is crucial for mosquito control to measure populations and plan how to handle them.

What to know about mosquito-borne illnesses

The mosquitoes that officials typically look out for are the ones that carry diseases, like malaria, dengue or West Nile, among others.

Thanks to mosquito control and air-conditioned homes, these diseases have become uncommon in the state.

However, one virus has caught the attention of Kristi Miley, a researcher at the University of South Florida.

Dengue cases have more than tripled in the state over the past five years.

From about 2010 to 2018, there were about 800 cases in which someone was bitten elsewhere but found to be sick in Florida, and about 100 in which someone was bitten in the state. From 2019 to 2024, travel-related cases increased to more than 3,000, and locally acquired cases jumped to more than 400. That rise could be higher considering that last year’s data may not be complete, Miley said.

“This is starting to be concerning,” she said.

Pasco County saw 11 cases of travel-related dengue and 13 cases of locally acquired dengue in 2024.

“Dengue is no longer a travel-related issue,” said Adriane Rogers, executive director of Pasco County Mosquito Control District, in an email to the Times.

Dengue has four different strains. If a person is infected with one strain, they may experience flu-like symptoms. If they are infected with a different strain later on, their immunity for the virus is lower and, in rare cases, they can die.

“The rise in local cases means we all have a role to play — from public health officials and clinicians to everyday residents,” Rogers said, adding that mosquito-borne diseases often go unreported.

Miley and her team are creating a model that predicts the risk of dengue in Florida based on weather factors and land use.

“At the end of the day, you have this risk model that potentially could be offered to mosquito control as a way to be more proactive,” she said.

It’s difficult because there is no uniform reporting of mosquito populations across the state. Miley relies on mosquito programs to offer their data.

Mosquito control officials in Florida meet annually to discuss trends and methodologies, and they often collaborate when an outbreak is occurring across county lines.

But mosquito control programs are ultimately silos, Miley said.

How mosquito control districts treat mosquitoes

In Tampa Bay, there’s typically a layered approach to attacking mosquitoes. The easiest and most effective way is getting to them before they can fly.

When they’re flying, “they’re hard to trap, and they’re also biting people and possibly spreading disease,” Scott said.

Mosquitoes need water to breed. Without it, they can’t thrive.

Most mosquito control programs breed mosquito-eating fish and give them out to the public for free. The fish, aptly named mosquitofish, have spoon-shaped mouths that can suck up the larvae wriggling on the water’s surface.

Mosquito officials also use larvicides and insecticides to target the insects. They often rear the bugs in-house to test their resistance levels, sometimes at state labs.

Mosquito control officials in Pinellas, Hillsborough and Pasco also respond to public requests to fight mosquito populations.

There are certain criteria, like a high number of mosquitoes found in an area, before mosquito officials can spray a larger area than a requested home or business, Berro said.

Officials use people, vans or even helicopters to treat areas where mosquitoes have become an issue.

Florida’s weather is a mosquito’s paradise

Florida’s warm weather means mosquitoes can survive through the seasons. Heat combined with rainfall can influence a mosquito’s life cycle.

In the summer, mosquitoes can go from egg to adult in three to five days. In the winter, it could take a week or longer.

The average lifespan of an adult mosquito can be anywhere from two weeks to two months, Scott said.

And climate change is extending warmer weather seasons, allowing mosquito populations to thrive longer.

Hurricanes can also prolong mosquitoes’ active time, dumping more rain and leading to more standing water.

“We’ve seen a vast increase in these extreme weather patterns, and the last couple of hurricane seasons have left a lot of debris,” Miley said.

Storm debris can sit out for weeks, providing a perfect breeding ground. That’s why experts say it’s so important to drain standing water.

Eradicating mosquitoes is not the goal, Rogers said. Some populations are pollinators or food sources for other animals. Instead, mosquito control seeks to keep dangerous populations at bay.

“It’s a delicate balance,” Rogers said.

The effort to hold back mosquito populations in Florida is massive. There is no silver bullet, Rogers said.

Instead, there are myriad methods, from complex science and expensive equipment to the sentinel chickens — still oblivious to their role in the persistent battle.

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Times staff writer Gabrielle Calise contributed to this report.

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