Can Sand Fleas Bite?

Yes, Tunga penetrans, commonly known as sand fleas or jiggers, do “bite,” but the behavior of these fleas is a bit different from typical biting insects. Only the female sand flea penetrates the skin. The female flea burrows into the skin, usually on the feet, toes, or under toenails. This is not a bite in the classic sense (like a mosquito bite) but an embedding. Once inside, it swells as it feeds on blood and lays eggs.

So, while it isn’t a “bite” like a mosquito or flea on a dog, the female sand flea does penetrate and feed on human skin, which is why it can cause significant discomfort and complications if untreated.

Do Sand Fleas Bite?

Sand fleas (Tunga penetrans) don’t “bite” in the conventional sense; instead, the female flea penetrates the skin to feed and lay eggs. The situations in which this occurs are very specific and predictable:

Barefoot or minimally protected feet: Walking, standing, or sitting on sandy or loose soil, especially in tropical and subtropical regions where sand fleas are endemic (parts of South America, the Caribbean, sub-Saharan Africa, and India). Children and adults who go barefoot on beaches, dirt floors, or outdoor sandy areas are at highest risk.
Contact with infested soil or floors: Areas where people or animals with flea infestations have been. The fleas live in sandy soil, dust, or floors of huts and homes, and can jump onto exposed skin.
Warm, dry conditions: Sand fleas are most active during dry, warm periods, often near the ground where the sun heats the sand. Wet or heavily shaded areas are less favorable for them.
Proximity to animals: Domestic animals like dogs and pigs can carry sand fleas. Walking barefoot in areas where these animals defecate or rest increases the likelihood of penetration.
Crowded, poorly maintained living conditions: Homes or villages with dusty floors, sand inside homes, or inadequate hygiene provide ideal conditions for sand flea activity.

Essentially, sand flea “bites” happen when bare skin contacts infested sandy or dusty ground, particularly the feet, toes, and under toenails. The fleas don’t actively chase humans—they rely on contact with exposed skin in favorable environments.

Sand Flea Bites

The risks associated with sand flea bites go beyond minor irritation. Because the female flea embeds itself in the skin to feed and lay eggs, the potential consequences can be significant, especially if left untreated:

Local Skin Reactions

Itching and irritation: Early penetration can cause itching, redness, and a small, raised bump.
Pain and discomfort: As the flea enlarges inside the skin, pressure and inflammation may cause tenderness, especially on the feet or under toenails.
Swelling and redness: The lesion can become inflamed, sometimes mimicking an abscess.

Secondary Bacterial Infection

Common bacteria: Staphylococcus and Streptococcus species may infect the lesion if hygiene is poor or if the flea is removed improperly.
Symptoms: Pus formation, increased pain, warmth, and swelling around the lesion.
Complications: Severe infections can lead to cellulitis, lymphangitis, or ulceration.

Tissue Damage

Ulceration: Persistent infestations or scratching may break the skin, leading to open sores.
Nail deformation: Fleas under toenails can cause permanent nail distortion or loss if repeatedly infested.
Gangrene (rare): Severe secondary infections, especially in immunocompromised individuals, can potentially lead to tissue necrosis.

Multiple Infestations

Heavy infestations: People walking barefoot in endemic areas may have dozens of embedded fleas at once, leading to significant discomfort, difficulty walking, and increased risk of infection.

Chronic Complications

Scarring: Recurrent infestations or improperly treated lesions may leave permanent scars.
Mobility issues: Severe or multiple infestations on the feet can impair walking.

Psychosocial Impact

Stigma and social embarrassment: Visible lesions on the feet or hands can affect social interactions, especially in children.
Economic impact: Difficulty walking can limit work or school attendance in endemic regions.

The main risk isn’t the flea itself but what happens after it embeds: inflammation, infection, and tissue damage. Proper prevention (closed-toe shoes, clean living areas) and careful, sterile removal are essential to minimize complications.

What Do Sand Flea Bites Look Like?

Sand flea “bites” from Tunga penetrans have a very distinctive appearance because the female flea actually burrows into the skin rather than just feeding on the surface:

Early Stage (Hours to 1–2 Days After Penetration)

Small, red, itchy bump, often mistaken for a mosquito bite or blister.
Usually 1–2 mm in diameter.
A tiny black dot may appear in the center, representing the flea’s exposed rear end for breathing and egg-laying.

Mature Stage (Several Days to 1–2 Weeks)

The bump enlarges as the flea feeds and swells with eggs.
Lesion becomes white or grayish, dome-shaped, and can reach 5–10 mm in diameter.
Black central spot remains visible, sometimes surrounded by a reddish halo.
The area can be painful or tender, especially when walking on the foot.

Late Stage / Complications

If left untreated, the lesion may ulcerate or become infected.
Secondary bacterial infection can cause pus, increased redness, and swelling.
Multiple lesions may cluster on toes, soles, or under toenails, sometimes deforming the skin or nails.

Common Locations

Feet and toes, especially under toenails or between toes.
Soles of the feet if barefoot in sandy soil.
Hands or fingers if working with soil or handling animals in endemic areas.

A classic sand flea lesion looks like a small, swollen nodule with a central black dot, often painful and itchy, sometimes surrounded by redness.

What To Do About Sand Flea Bites

If you suspect you’ve been “bitten” by sand fleas, the key is prompt, careful action to prevent infection and complications:

Avoid Scratching or Squeezing

Scratching can push the flea deeper, rupture it, or introduce bacteria.
Never attempt to crush the flea under the skin.

Clean the Affected Area

Wash the site gently with soap and clean water.
Avoid harsh chemicals or aggressive scrubbing, which can damage the skin.

Remove the Flea Safely

Only if sterile tools and proper knowledge are available.
Methods include using a sterilized needle or small surgical blade to carefully extract the flea.
Do not use your fingers or unsterilized tools, as this can cause infection.
After removal, clean the wound again with antiseptic and apply a sterile bandage.

Monitor for Infection

Signs of infection: redness, warmth, swelling, pus, or increasing pain.
If these occur, seek medical attention promptly. Antibiotics may be required.

Pain and Itch Relief

Over-the-counter antihistamines can reduce itching.
Topical antiseptics or antibiotic ointments can help prevent secondary infection.
Pain can be managed with standard analgesics like acetaminophen or ibuprofen.

Prevent Future Infestations

Wear closed-toe shoes when walking in sandy or dusty areas.
Keep living areas clean and avoid barefoot contact with infested soil.
Treat domestic animals if they may harbor sand fleas.

Seek Professional Care if

You have multiple embedded fleas.
The lesion shows signs of infection.
You are immunocompromised or have diabetes, which increases the risk of complications.

The priority is hygienic flea removal, infection prevention, and careful monitoring. Left untreated, sand flea lesions can become painful, infected, or cause permanent tissue damage.