Chigger bites

Chiggers

Chiggers Trombiculidae (e.g., Trombicula / Eutrombicula alfreddugesi) Chiggers are the tiny larvae of mites; only the larva bites, and its feeding causes intense itching and small red welts. Contrary to popular belief, chiggers don't burrow into the skin or suck blood.

What chiggers are

A chigger is the larva of a mite in the family Trombiculidae. Only this six-legged larval stage feeds on people and animals; the later nymphs and adults are predators of insect eggs and very small arthropods.^{[3][1][5][10][13]}

Several species occur in the United States, and Missouri Extension names Trombicula alfreddugesi as the one most often encountered; a StatPearls review calls it Eutrombicula alfreddugesi, and the Missouri Department of Conservation lists Eutrombicula as another name for the genus. The larvae are about 1/150 inch across (StatPearls gives 0.15 to 0.3 mm long), too small to see without magnification, and yellow to reddish according to Ohio State, light red to orange according to StatPearls.^[2][3][7][9]

Their usual hosts are rodents, birds, snakes, toads and other animals; people are accidental hosts. Larvae climb to the tips of grass blades and other plants and wait for a passing animal or person. The Missouri Department of Conservation puts reptiles and birds first, with mammals, people included, as secondary, almost accidental hosts.^{[2][5][3][7][10]}

• The bigger red mites on patios, walls and lawn furniture are usually not chiggers. Ohio State says red velvet mites, concrete mites and clover mites get blamed but don't bite people.^[3]

Where and when you pick them up

Chiggers live in damp places with tall grass, weeds and low brush, in berry patches and along the edges of woods. They are patchy: one person can sit in a heavily infested spot and get bitten badly while someone a few yards away gets nothing.^[2][1][7]

Texas A&M AgriLife points to tall grass around ponds, creeks and rivers and says that warm weather above 80 degrees combined with moisture sets up infestations, though even mowed lawns can occasionally hold chiggers.^[5]

Temperature matters. The Missouri Department of Conservation says chiggers are most active in the afternoon and when the ground is about 77 to 86 F; they become inactive below 60 F, the ones that bite are killed below 42 F, and they avoid objects hotter than 99 F, so sun-baked rocks are usually chigger-free. Ohio State says the overwintering adults come out to mate and lay eggs when temperatures rise above 60 degrees F.^[7][3]

Adults spend the winter in the soil. Missouri has two to three generations a year, so bites are possible from May until the first killing frost; Ohio State sees the most chiggers from June through August, and AgriLife calls late spring and early fall the prime seasons in Texas. MedlinePlus says bites commonly occur in the summer and fall.^[2][3][5][1]

How chiggers bite (and the burrowing myth)

Once on a person, chiggers crawl upward until they reach a spot where clothing fits tight against the skin or the skin is thin. That is why bites cluster at the tops of socks and shoes, under waistbands and bra bands, behind the knees, in the groin and in the armpits.^[2][3][4][7]

Chiggers do not burrow into skin and do not suck blood. They pierce the skin, inject saliva with digestive enzymes, and sip the dissolved skin cells through a hardened feeding tube called a stylostome that forms in the skin.^{[2][3][4][5][9][13]}

Left undisturbed, a chigger keeps feeding for days: Ohio State says 2 to 4 days on its animal hosts, Missouri Extension three or four days. On people they come off much sooner. They are brushed, scratched or washed off, and StatPearls says the larvae rarely stay attached to humans for more than 48 hours. Missouri Extension adds that chiggers die soon after they are dislodged.^[3][2][9]

Ohio State notes that a chigger can get trapped in the swelling skin and die there, which can add to the inflammation, but it is still not burrowing.^[3]

What chigger bites look like

MedlinePlus lists severe itching and red, pimple-like bumps or hives as the main symptoms. The bite itself is painless, and itching starts several hours after the chiggers attach. Medical reviews describe itchy red papules and small blisters (papulovesicles) with redness and a variable amount of swelling around them.^[1][9][10]

MedlinePlus notes that a rash which stops where the underwear meets the legs is often a clue that chiggers are the cause.^[1]

• Timing: itching usually starts several hours after the chiggers attach, MedlinePlus says. The larvae are usually gone within a day or two, but StatPearls says the itching, inflammation and local allergic reaction may last for weeks.^[1][9]
• How long: a dermatology review says most bites heal on their own within a couple of weeks, so only symptom relief is needed. In an Ohio emergency department series of children with chigger-related penile swelling, itching lasted 0 to 14 days (average 3.0).^[10][12]
• Where on the body: chigger bites tend to run along the sock and belt lines, while mosquito bites are on exposed skin, according to a family-medicine review; MedlinePlus lists the waist, the ankles and warm skin folds. Ohio State says chigger bites rarely occur on uncovered skin.^[11][1][3]
• Diagnosis: a provider can usually tell from the pattern of the rash and your history of time outdoors. StatPearls says the tiny larva is seldom found on the skin; MedlinePlus says a magnifying scope may be used to look for it.^[9][1]

Treating the itch

Treatment aims to stop the itching. MedlinePlus says antihistamines and corticosteroid creams or lotions may help, and antibiotics are not necessary unless a skin infection develops. StatPearls describes the same approach (oral antihistamines or topical corticosteroid creams), and a dermatology review adds topical anti-itch products.^[1][9][10]

Scratching can cause a secondary infection; StatPearls also lists bacterial superinfection as an uncommon complication.^[1][9]

• Nail polish, bleach and similar home remedies are aimed at a mite under the skin that isn't there. Chiggers don't burrow, so there is nothing to smother; Texas A&M AgriLife's Travis County entomologist calls nail polish useless.^[4][5][3]
• By the time the itching starts, the chiggers are usually gone, so treatment is about easing symptoms while the reaction runs its course.^{[4][5][9][10]}

When to see a doctor

MedlinePlus advises contacting your health care provider if the rash itches very badly, or if symptoms get worse or don't improve with treatment. Signs that scratched skin has become infected are another reason to be seen, since antibiotics are only needed for an infection.^[1]

For severe cases, a dermatology review lists a steroid injection into the bite (intralesional triamcinolone acetonide), which a clinician gives.^[10]

Young boys can get sudden swelling of the penis from chigger bites in summer, sometimes called summer penile syndrome. In a series of ninety-four children seen at an Ohio children's hospital emergency department from June through September, itching was common, a third had pain on urination, and treatment was usually an oral antihistamine and cold compresses; the swelling lasted 1 to 18 days, 4.1 days on average.^[12]

Disease: StatPearls says the reaction is usually mild and self-limited, but bites may rarely transmit disease. The chiggers involved differ by region: Eutrombicula alfreddugesi in the southern United States, Trombicula autumnalis in Europe and the Leptotrombidium group in the Asia-Pacific region. CDC's Yellow Book counts chiggers among the biting arthropods travelers should avoid because some transmit disease-causing pathogens.^[9][8]

Right after you've been in chigger habitat

Take a warm shower and scrub with a washcloth as soon as you can. Missouri Extension says a shower with vigorous scrubbing within an hour or two of exposure greatly reduces the number of bites, but once itching has started it is probably too late for bathing to help much.^[2][5][3][7]

• Change out of the clothes you wore and launder them before wearing them again. Ohio State suggests the hot setting.^[2][4][3]

Preventing chigger bites

The surest step is to avoid chigger habitat. When you can't, keep chiggers on the outside of your clothes and give a repellent time to work on them.^[2][5][4][1]

• Wear long pants and long sleeves rather than shorts and sandals, tuck pant legs into socks or boots, and button cuffs and collars. Tightly woven fabrics are harder for chiggers to get through.^[2][4][5][7]
• Don't sit on the ground in grassy or brushy areas.^[4]
• Use a repellent containing DEET or picaridin. Missouri Extension says to apply it to clothing from the feet up and reapply every two to three hours; MedlinePlus says DEET on skin and clothing can help prevent bites, and NPIC lists chiggers among the pests picaridin repels. A dermatology review also recommends covering the skin and using DEET on skin and clothing, and a family-medicine review names DEET at 10% to 35% or picaridin at 20% as the best way to prevent insect bites in general.^{[2][1][6][4][10][11]}
• Ohio State also lists oil of lemon eucalyptus products. Sulfur powder on clothing works too, Missouri Extension says, but it smells strongly.^[3][2][5]
• Permethrin products go on clothing only, never on skin. Spray the clothes and let them dry before you put them on; AgriLife notes the protection lasts longer than with repellents. CDC's Yellow Book says 0.5% permethrin-treated clothing repels and kills chiggers, ticks and mosquitoes; for travel it says to treat items 24 to 48 hours before packing so they can dry.^[2][5][8]

Chiggers in the yard

Mowing the lawn and removing unneeded brush and weeds is the most effective area control, according to Missouri Extension. Chiggers avoid direct sunlight and seldom infest well-kept, mowed areas; Ohio State adds opening up the landscape to more sun and air.^[2][3][4]

To check whether your yard has chiggers, Ohio State suggests laying a square of black paper or cardboard in the grass for 10 minutes. The yellowish-red mites show up against the black.^[3]

• Spraying gives limited, temporary control, lasting a few days or weeks according to Missouri Extension. Ohio State doesn't generally recommend it because populations rebound, though targeted spot treatment of hot spots can knock numbers down for a while.^[2][3]
• If you do treat, target the overgrown spots and lawn edges rather than the whole lawn. Missouri Extension recommends a single application from late April through mid-June.^[2][4]
• Products sold for chiggers contain pyrethroids such as bifenthrin or permethrin. Ohio State warns these broad-spectrum insecticides can harm beneficial insects and pollinators: don't spray blooming plants or while pollinators are flying, and follow the label, including the re-entry time for people and pets.^[3][2]

When the itch isn't chiggers

Ohio State reminds readers that poison ivy, mosquitoes, skin allergies and even contact with turfgrass blades can also cause itchy red welts. Extension staff can't diagnose skin problems, so a severe or puzzling reaction is a reason to see a medical professional.^[3]

Many bites look alike. A family-medicine review says bites from fleas, bed bugs, biting flies and mosquitoes all show up as itchy pink bumps, and where the bites are helps sort them out: flea bites are usually on the ankles, mosquito bites on exposed skin, and chigger bites along the sock and belt lines.^[11]

Common questions

Do chiggers burrow under your skin?

No. They attach at the surface, inject saliva and feed through a tube that forms in the skin, then drop off or get brushed off. They don't burrow and don't suck blood.^{[2][3][4][5][9]}

How long do chigger bites itch?

Itching usually starts several hours after the chiggers attach. Most bites heal within a couple of weeks, though StatPearls says the reaction may last for weeks.^[1][10][9]

Does nail polish kill chiggers?

No. Chiggers don't burrow, so there is no chigger under the skin to smother. Texas A&M AgriLife calls nail polish useless for this.^[4][5]

What helps chigger bites stop itching?

MedlinePlus says antihistamines and corticosteroid creams or lotions may help. Contact a provider if the itching is very bad or the rash gets worse or doesn't improve.^[1][9][10]

Can chiggers live in your bed or house?

Chiggers die soon after they are knocked off a host, and only the larvae bite. Washing the clothes you wore outdoors takes care of any still on them.^[2][3][4]

Do repellents work on chiggers?

Yes. Repellents with DEET or picaridin work against chiggers, and permethrin-treated clothing adds protection. CDC's Yellow Book says permethrin-treated clothing repels and kills chiggers.^{[2][1][6][5][8]}

Do chiggers spread disease?

StatPearls says the reaction is usually mild and self-limited, and bites may rarely transmit disease. The species it names for the southern United States is Eutrombicula alfreddugesi; the Leptotrombidium group it lists is in the Asia-Pacific region. See a provider if the rash gets infected, gets worse or doesn't improve.^[9][1]

Sources

1. NIH National Library of Medicine, MedlinePlus, “Chiggers (Medical Encyclopedia).” medlineplus.gov/ency/article/001333.htm (accessed 2026-11-11)
2. University of Missouri Extension, “Chiggers (G7398).” extension.missouri.edu/publications/g7398 (accessed 2026-11-11)
3. Ohio State University Extension (Ohioline), “Chiggers (ANR-0182).” ohioline.osu.edu/factsheet/anr-0182-0 (accessed 2026-11-11)
4. Texas A&M AgriLife Extension, Urban Programs Travis County, “Chiggers.” travis-tx.tamu.edu/?p=15932 (accessed 2026-11-11)
5. Texas A&M AgriLife Today, “Chigger season tips to beat the itch.” agrilifetoday.tamu.edu/2024/05/24/chigger-season-tips-to-beat-the-itch/ (accessed 2026-11-11)
6. National Pesticide Information Center, “Picaridin General Fact Sheet.” npic.orst.edu/factsheets/PicaridinGen.html (accessed 2026-11-11)
7. Missouri Department of Conservation, “Chiggers (Field Guide).” mdc.mo.gov/discover-nature/field-guide/chiggers (accessed 2026-11-11)
8. Centers for Disease Control and Prevention, “CDC Yellow Book: Mosquitoes, Ticks, and Other Arthropods.” www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods.html (accessed 2026-11-11)
9. StatPearls Publishing, NCBI Bookshelf (PubMed 30860763), “Alexander L, Chen RJ, Buckley CJ. Chigger Bites and Trombiculiasis. StatPearls, 2024.” pubmed.ncbi.nlm.nih.gov/30860763/ (accessed 2026-11-11)
10. Cutis (PubMed 28686755), “Hohenberger ME, Elston DM. What's eating you? Chiggers. Cutis 2017;99(6):386-388.” pubmed.ncbi.nlm.nih.gov/28686755/ (accessed 2026-11-11)
11. American Family Physician (PubMed 24364549), “Juckett G. Arthropod bites. Am Fam Physician 2013;88(12):841-847.” pubmed.ncbi.nlm.nih.gov/24364549/ (accessed 2026-11-11)
12. Pediatric Emergency Care (PubMed 9583392), “Smith GA et al. The summer penile syndrome: seasonal acute hypersensitivity reaction caused by chigger bites on the penis. Pediatr Emerg Care 1998;14(2):116-118.” pubmed.ncbi.nlm.nih.gov/9583392/ (accessed 2026-11-11)
13. Acta Tropica (PubMed 39366499), “Pesenato IP, Bassini-Silva R, Jacinavicius FC. A review on trombiculiasis. Acta Trop 2024;260:107420.” pubmed.ncbi.nlm.nih.gov/39366499/ (accessed 2026-11-11)