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Fire Ant Bites

Fire ant bites happen when a certain type of venomous ant stings. The stings cause a burning sensation, then itchy welts, often in a circular pattern. The welts turn into blisters. Most people can treat fire ant bites at home with antihistamines, over-the-counter steroid creams and cold compresses. But sometimes, the stings can cause systemic or life-threatening reactions.

Overview

What are fire ant bites?

A fire ant bite occurs when a particular type of aggressive, venomous ant stings your skin.

The bites are painful, itchy and usually on your legs and feet. Rarely, the venom causes a life-threatening reaction.

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What does a fire ant look like?

A fire ant red-tinged insect. Its size ranges from 1 millimeter (mm) (the tip of a pencil) to 5 mm (the size of a pencil eraser). It has six legs and two pinching mandibles that protrude from its head. It has a pouch of venom and a stinger on its rear end.

Where do fire ants live?

Fire ants are common in the United States, especially in the southeast.

Fire ants (Solenopsis invicta and S. richteri) were accidentally imported from South America to Alabama in the 1930s.

The ants live in large numbers in colonies or nests in the ground.

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Symptoms and Causes

What happens when fire ants bite you?

Fire ant bites typically occur when someone accidentally steps on an area of the ground where the insects live. Stings often occur on the exposed skin of your feet, ankles and legs. Fire ants can also attack animals, including pets.

Contact with a fire ant nest will prompt numerous ants to swarm and attack and bite exposed skin.

When a fire ant bites, it attaches its mandibles to your skin. Then, it curves back and sticks its stinger into your skin, injecting venom. It can sting multiple times at once, moving in a circular direction, sometimes, delivering seven or eight stings at a time.

The ants may repeatedly sting you unless you kill them or remove them from your skin.

What does a fire ant bite look like?

The symptoms of a fire ant bite happen in stages:

  1. First, you’ll experience a burning or stinging sensation.
  2. Within about an hour, itchy bumps or welts will develop. The bumps are usually in a circular or semicircular pattern and typically last for several hours.
  3. After several hours, blisters will develop where the bumps were located. They’re usually very itchy.
  4. About a day or so later, the blisters fill with a yellow or white pus-like fluid. They go away within seven to 10 days.

Some people experience a more severe reaction:

  • Local reaction: A localized reaction involves symptoms in the same region of your body but beyond the bite location. For example, one sting on your calf may cause swelling in your entire lower leg. Local reactions usually last a couple of days.
  • Systemic reaction: Your entire body may react to a sting. Symptoms may include stomach cramps, diarrhea, nausea and vomiting, swollen tongue, or trouble breathing or swallowing.
  • Anaphylaxis: Rarely, fire ant bites can cause anaphylaxis, a severe, life-threatening allergic reaction. Symptoms include dizziness, a drop in blood pressure, loss of consciousness and/or cardiac arrest.
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Diagnosis and Tests

How are fire ant bites diagnosed?

You or your healthcare provider can often diagnose fire ant bites based on:

  • Identification of the insect involved.
  • Your skin’s appearance in the first several hours.
  • Characteristic symptoms, such as itchiness or burning.

Management and Treatment

What should I do for fire ant bite treatment?

You can treat mild fire ant bites at home with the following steps:

  1. Slapping or brushing the ants off of your skin.
  2. Washing the affected skin with soap and cold water.
  3. Taking an oral antihistamine (an allergy medication, such as Benadryl®) may help the itchiness.
  4. Applying hydrocortisone cream on the affected skin two times a day should help reduce itchiness and the rash.
  5. Using cold compresses (ice packs) as needed can help reduce pain and swelling.

More serious systemic or anaphylactic reactions may require:

If the blisters break and become infected, you may need antibiotics.

Should you pop a fire ant bite?

Don’t squeeze or pop the blisters. Doing so can lead to infections and scars.

Prevention

How can I prevent fire ant bites?

Certain strategies can help you reduce your risk of insect bites, including fire ant stings.

  • Apply insect repellent to your exposed skin and clothes.
  • Be careful whenever you lift something off the ground, such as logs, because fire ants may be underneath.
  • Contact a pest-control specialist if you see fire ants or colonies on your property.
  • Don’t disturb any nests, colonies or mounds.
  • Wear long sleeves and pants. Tuck your pants into your socks or shoes to cover any exposed skin.
  • Wear shoes when walking outside.

Outlook / Prognosis

How long do fire ant bites last?

Most reactions to fire ant stings last about a week and don’t require much treatment except as mentioned above. Only about 2% of stings lead to severe reactions.

The blisters can leave scars, especially if you pick or pop them.

If you have a serious reaction to fire ant stings, consider consulting with an allergist after you recover. They may recommend allergy testing or a prescription for an epinephrine injector. This can help you in the event of a future fire ant sting.

Living With

When should I seek medical attention after a fire ant bite?

Seek immediate medical attention if you develop any signs of a systemic or anaphylactic reaction. Although anaphylaxis is rare, it can become life-threatening quickly, so quick action is key.

When should I seek medical attention for blisters?

If you have any blisters or think a blister may be infected, contact your healthcare provider or a dermatologist.

It’s important to seek medical attention if you develop any of the following symptoms:

  • Flu-like symptoms, such as fever, chills or body aches.
  • Increasing redness or red streaks on your skin.
  • Pain or itchiness that gets worse or doesn’t improve over a few days.

A note from Cleveland Clinic

Fire ants are aggressive, venomous insects that sting. They cause painful, intensely itchy welts that turn into blisters. Though rare, fire ant venom can cause a life-threatening reaction. Seek immediate medical attention if you have any systemic symptoms.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/28/2022.

Learn more about our editorial process.

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