Chicken Mites — Identification, Treatment, and Prevention
The invisible pest that drains your hens overnight.
What's in this guide
What is it?
Chicken mites are external parasites that feed on hen blood. The two most common in US backyard flocks are Red Mites (Dermanyssus gallinae), which live in coop cracks and feed at night, and Northern Fowl Mites (Ornithonyssus sylviarum), which live on the hen and feed 24/7. Both can drain a hen to death within weeks if untreated, and they reduce egg production dramatically.
What are the symptoms?
- Pale combs and wattles (anemia from blood loss)
- Decreased egg production
- Restless hens that refuse to enter the coop at night
- Visible tiny red, gray, or black specks on the hen's skin (especially around the vent, under wings, and base of feathers)
- Dark gritty 'pepper specks' on roost bars (mite feces)
- Hens scratching, plucking feathers, or rubbing against perches constantly
- White nits (eggs) on feather shafts near the skin
- Scaly leg appearance (different mite — scaly leg mite — but related family)
What causes it?
- New birds added without quarantine — the #1 way mites enter a flock. Always quarantine new birds 30 days.
- Wild bird contact — sparrows, starlings, and pigeons carry chicken mites into coops.
- Dirty coop with deep cracks — Red Mites need hiding spots. Plywood-only coops with sealed joints fare better than coops with multiple wood layers and gaps.
- Warm humid weather — mite populations explode in summer.
- Used coop equipment — secondhand nest boxes, roost bars, or coops can carry mite eggs that survive months without a host.
How to treat it — step by step
- Treat the hens: dust each hen with permethrin powder (5-10%) or spray with diluted permethrin (0.5%). Focus on the vent area, under wings, and base of feathers. Repeat in 7-10 days to kill newly hatched mites.
- Treat the coop: empty all bedding, scrub roost bars and nest boxes with hot soapy water, dry thoroughly, then spray all cracks with permethrin or Elector PSP. Pay extra attention to underside of roost bars where Red Mites hide.
- Replace bedding with fresh deep pine shavings after treatment.
- Add diatomaceous earth (food-grade) to dust bath areas and lightly into nest box bedding — this kills future hatching mites.
- For severe infestations: ask a poultry vet about prescription off-label treatments. Ivermectin and similar macrocyclic lactones are sometimes used off-label by vets but are not FDA-approved for laying hens in the US and require a veterinarian to set a valid egg-withdrawal period before any eggs are eaten. Do not self-dose with livestock ivermectin intended for cattle, sheep, or horses.
How to prevent it
- Quarantine new birds 30 days before adding to the flock
- Provide a chicken dust bath in the run — hens self-treat by dusting in dry earth and ash
- Inspect roosts and nest boxes monthly at night with a flashlight
- Sprinkle food-grade diatomaceous earth in coop corners and under nest box bedding
- Keep wild birds out — cover the run with hawk-proof mesh, remove spilled feed
- Buy or build coops with smooth surfaces and fewer cracks — metal frames in our walk-in chicken runs have fewer mite hiding spots than complex wooden builds
When to call a vet
- Hen is severely anemic (pale comb, weak, listless) — needs blood-rebuilding electrolytes and possibly vet care
- Skin damage from constant scratching shows infection (warm, swollen, oozing)
- Mite infestation has not responded to two rounds of permethrin
- Multiple birds in the flock are dying despite treatment
Frequently asked questions
Do mites bite humans?
Red Mites and Northern Fowl Mites can bite humans temporarily but cannot live on us — they need bird hosts to reproduce. Mite bites on humans cause itchy red welts that resolve in a few days.
How fast do mite populations grow?
Explosive — a single fed female Red Mite can lay 30-50 eggs in her 2-3 month lifespan. A handful of mites can become thousands in 4-6 weeks under warm conditions.
Are chicken mites the same as lice?
No. Lice are larger (visible to the naked eye at 2-3 mm) and live their entire life on the bird. Mites are smaller, blood-feeders, and many species hide off the bird during the day.
Can I eat eggs from mite-treated hens?
Depends on the treatment. Permethrin dust: yes, eggs are safe immediately. Ivermectin pour-on: 7-14 day withdrawal. Always check the label of your specific treatment.
How often should I treat for mites?
Preventatively: dust bath access + monthly inspection. After confirmed infestation: treat birds + coop, repeat in 7-10 days, then inspect monthly for 3 months.
What's the cheapest mite treatment that works?
Permethrin dust ($8-15 per bag, treats a 6-hen flock 4-5 times) and food-grade diatomaceous earth ($15-25 per bag, ongoing use). Both are effective for moderate infestations. Severe cases need stronger treatments like Elector PSP.
Related chicken care topics
🏠 Browse coops sized to prevent the underlying cause
Most flock health issues trace back to overcrowded, poorly-ventilated, or hard-to-clean coops. A right-sized coop with proper bedding access is the single biggest prevention tool.
Browse all chicken coops →Sources cross-checked with University of California Davis Veterinary Medicine Extension, Mississippi State Extension Poultry, Penn State Extension, and the Merck Veterinary Manual. Not veterinary advice — consult a licensed avian or poultry vet for sick birds.