Stop your rain barrel from becoming a mosquito magnet

3 easy fixes to catch rain and not biting bugs

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JACKSONVILLE, Fla. – As we move through our driest season, many homeowners are looking for ways to conserve water before the regular afternoon thunderstorm cycle returns this summer.

One popular solution is rain barrels.

Painting a rain barrel at Ocoee’s ‘Spring into Conservation’ event. (Copyright 2025 by WKMG ClickOrlando - All rights reserved.)

These simple tools collect runoff from your roof, allowing you to store water for later use—perfect for keeping gardens, lawns, and potted plants hydrated while cutting down on your utility bill.

Over the course of a year, a single rain barrel can save hundreds of gallons of water and reduce stormwater runoff that leads to pollution in local waterways.

But there’s a catch: if not properly maintained, rain barrels can quickly become breeding grounds for mosquitoes.

A mosquito lands on a person's arm. (Ravi Kant via Pexels.)

A study from the University of Illinois found that over half of the residential rain barrels surveyed had mosquito larvae inside.

That’s not just a nuisance—it’s a public health concern. Mosquitoes thrive in standing water and can carry serious diseases like West Nile virus.

Fortunately, researchers found three simple and effective ways to mosquito-proof your rain barrel without giving up the benefits.

1. Use a mesh cover

Augusto Cesar, a city worker who combats endemic diseases, places netting over a water tank where mosquitoes can breed, to help eradicate the Aedes aegypti mosquito which can spread dengue, in the Morro da Penha favela of Niteroi, Brazil, Friday, March 1, 2024. (AP Photo/Bruna Prado) (Copyright 2024 The Associated Press. All rights reserved)

A fine mesh screen—similar to window screening—secured over the top of the barrel can keep adult mosquitoes from laying eggs in the water. Make sure it’s tight-fitting and covers all openings, including overflow holes.

Tip: Zip ties, bungee cords, or even a repurposed screen frame can keep the mesh in place, even through wind and summer storms.

2. Treat the water

Bti dunk used to kill mosquito larvae. (CDC)

Products like Mosquito Dunks use a naturally occurring bacteria (Bacillus thuringiensis israelensis, or Bti) that targets mosquito larvae without harming plants, pets, or beneficial insects.

Tip: Drop in a dunk or a few granules once a month. They’re inexpensive, widely available at garden stores, and highly effective.

3. Add a few goldfish

A few goldfish will do a good job eating up the mosquito larve. (Ariel Camilo/freeimages.com)

If your barrel is uncovered or part of a larger pond-style system, goldfish can help by feeding on mosquito larvae.

Tip: Make sure the barrel stays shaded and filled, and avoid using any chlorinated water. One or two goldfish are all you need—plus, they make a fun addition for kids to watch.

Rain barrels are a smart, sustainable tool for Northeast Florida homeowners—but only when they’re managed properly.

If you’ve got one or are planning to install one, take these extra steps to avoid turning a water-saving solution into a mosquito motel.

Have a rain barrel setup at home? Share your tips or photos with us on the News4JAX Insider page.


About the Author
Mark Collins headshot

After covering the weather from every corner of Florida and doing marine research in the Gulf, Mark Collins settled in Jacksonville to forecast weather for The First Coast.

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