The Nevada County Environmental Health Department Vector Control Program will be holding Mosquito Fish Giveaways on five Thursday afternoons throughout May and June. Mosquito Fish can consume large quantities of insect larvae in your pond or other standing bodies of water. By reducing the mosquito population, you can reduce your risk of contracting mosquito-borne diseases including the West Nile Virus.

Mosquito Fish in Transportation Tank

“Our mosquito fish giveaways are one of our most popular events each year and are important to reducing mosquito larvae to prevent the spread of  West Nile Virus. This year we added eating tubes to our fish tanks, which helped our fish survive the winter and improved the survival of offspring, giving us more fish to distribute to the community,” said Amy Irani, Environmental Health Director.  


Time: 12:00 p.m. to 2:00 p.m. 
Location: In the Eric Rood Administrative Building Parking Lot (950 Maidu Ave, Nevada City)
How to Participate:  Drive-thru pick-ups only; please remain in your car. Containers will be provided to safely take the fish home.

  • May 5th 
  • May 19th
  • June 2nd
  • June 16th
  • June 30th      

About Mosquito Fish & the Best Environments for them to Thrive

The mosquito fish need to be delivered to your pond within two hours. The fish will eat mosquito larvae in ponds, watering troughs, and unused swimming pools. 

File photo of a prior fish giveaway

These fish are not native; they are invasive species. These fish are only meant for closed/stagnant ponds and should not be placed into ponds that can drain into the local creeks and streams. This can have negative impacts on the native ecosystem. If your pond has outlets, please do not acquire these fish. 

If your pond already has larger fish in it, you don’t need mosquito fish. The larger fish will eat the smaller mosquito fish.  Also, the larger fish will eat mosquito larva, and certainly, their smaller offspring will eat larvae too.  Nevada County Environmental Health can inspect your water source and offer other options as needed.

In situations where a property has temporary, seasonal ponds, drainages, or ditches and they cannot be manually drained, store-bought bacterial larvacide products such as BTI can be used. Most home-use larvacide products are harmless to the environment and will not hurt people, pets, or wildlife when used properly and according to label directions. These products can often be found at various hardware, garden, or pond supply stores. Also, the Nevada County Environmental Health Department provides on-site service visits for treatment requests. Call the Vector Control Program at 530-265-1500.

To learn more about vector management, visit our page on Mosquito Fish.