Mosquito Information

Prevent bites and use insect repellents safely

About Mosquito Bites

Almost everyone has experienced a mosquito bite. The red bump and itching are usually caused by an allergic reaction to mosquito saliva.

In some regions, mosquitoes can also transmit diseases to people, including West Nile virus and other forms of encephalitis. Mosquitoes can also transmit diseases and parasites that affect dogs and horses, including dog heartworm and eastern equine encephalitis.

The best protection is to reduce exposure, wear appropriate clothing, use an EPA-registered insect repellent as directed, and remove standing water where mosquitoes can breed.

Illustration of a mosquito
Mosquitoes are most active around dawn and dusk.

Preventing Mosquito Bites

  • Use an EPA-registered insect repellent when outdoors, especially around dawn and dusk when many mosquitoes are most active.
  • Wear long sleeves, long pants, socks, and a hat when mosquitoes are numerous.
  • Apply sunscreen first, allow it to dry, then apply insect repellent over it if you are using both products.
  • Reapply repellent only as often as the product label directs.
  • Use window and door screens, and repair holes or tears to keep mosquitoes out of enclosed spaces.
  • Once a week, empty, scrub, turn over, cover, or discard items that hold water, such as buckets, tires, toys, birdbaths, flowerpot saucers, and trash containers.

Choosing a Repellent

Look for an EPA registration number on the product label. When used as directed, EPA-registered repellents are evaluated for effectiveness and are recommended for protection against mosquito bites.

  • DEET A widely used, effective active ingredient. Choose the lowest concentration that provides the protection time you need and follow the label exactly.
  • Picaridin Another effective EPA-registered repellent option. It is also known as KBR 3023 or icaridin outside the United States.
  • IR3535 An EPA-registered repellent ingredient that can be an option for people who prefer an alternative to DEET or picaridin.
  • Oil of lemon eucalyptus or PMD Plant-derived repellent options. Do not use oil of lemon eucalyptus or PMD products on children under age 3 unless the product label specifically says it is appropriate.
  • 2-Undecanone Another EPA-registered active ingredient that may be listed on some repellent products.
  • Natural products CDC and EPA recommend EPA-registered repellents for protection against mosquito-borne germs; the effectiveness of non-registered “natural” products may not be established.

Using Repellents Safely

  • Apply repellent only to exposed skin and/or clothing, exactly as directed on the product label. Do not apply it under clothing.
  • Do not use repellent on cuts, wounds, or irritated skin.
  • Keep repellent away from the eyes and mouth. Apply sparingly around the ears.
  • Do not spray repellent directly onto the face. Spray it into your hands first, then apply it carefully to your face.
  • Do not let children handle repellent or apply it to their own hands. Apply it to your own hands first, then to the child.
  • Do not spray repellent in enclosed areas, breathe in the spray, or use it near food.
  • Use only enough repellent to cover exposed skin and/or clothing. A thin, even layer is usually sufficient.
  • After returning indoors, wash treated skin with soap and water. Wash treated clothing before wearing it again.
If you suspect a reaction: Stop using the product, wash the treated skin, and contact Poison Control at 1-800-222-1222 in the United States. If medical care is needed, take the repellent container with you.

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