Health

Chicken Mites and Lice: Identification and Treatment Options for Backyard Flocks

Field guide · Updated October 13, 2026 · about 4 min read

External parasites are among the most common problems in backyard flocks, and they cost eggs: University of Florida researchers note that lice can reduce egg production by as much as 10%, and heavy infestations by up to 20%. The key to treating them is knowing which pest you have, because the two main mites live in completely different places.

Important: This page summarizes extension guidance. It does not give doses. Every pesticide must be used exactly as its label directs, including whether it is approved for birds, for premises or both, age limits, re-treatment intervals and any egg or meat restrictions. Approved products change; ask your county extension office or a poultry veterinarian what is currently registered in your state.

Know your pest

	Northern fowl mite	Chicken red mite (roost mite)	Chicken body louse
Scientific name	Ornithonyssus sylviarum	Dermanyssus gallinae	Menacanthus stramineus
Where it lives	Always on the bird, most numerous around the vent	Off the bird, in cracks, crevices, roosts, nests and litter	Entire life on the bird, often around the vent
When active	Day and night	Feeds at night, hides by day	Constantly on host
Feeds on	Blood	Blood (red after feeding, black otherwise)	Skin scales, scabs and feathers — not blood
Signs	Blackened vent feathers from dried blood and mite droppings; scabby skin	Lesions on breast and legs; mites in crevices at night	Visible lice and egg clusters at feather bases
Survival off host	About 2–3 weeks	Up to 34 weeks	About a week
Life cycle	As little as 5 days	As little as 7 days	Roughly 1–3 weeks

Compiled from University of Kentucky ENTFACT-516, UC ANR Publication 8162 and University of Georgia Extension. Sources differ slightly on life-cycle length; Kentucky gives 7–10 days egg-to-adult for both mites, and UGA gives 18–21 days for the body louse.

Both mites are about 1/25 inch long, and both can bite people without infesting them (Kentucky). Wild birds, new birds, used cages and second-hand coops are common sources: Kentucky lists wild birds and new birds for northern fowl mites, and new birds, transport cages and used shelters for red mites. UGA adds that pigeons are a common wild host of the chicken mite.

How to inspect

Northern fowl mite: Part the feathers around the vent of several birds every two weeks, using a flashlight or bright daylight — light makes mites move and easier to spot. Mites may also show up on collected eggs (Kentucky).
Red mite: Check at night. Look in cracks, crevices, perches and manure on the floor for clusters of resting mites (Kentucky). Nest boxes are a common hiding place (UGA).
Lice: UC ANR recommends checking the vent, breast and thighs at least twice a month for lice or egg clusters; UGA suggests at least monthly checks of birds and nests.
People: Unexplained itching or rashes in whoever tends the flock can be a clue (UGA).

Treatment options extension services list

Principles first

Match the treatment to where the pest lives. For northern fowl mites and lice, treat all birds at the same time, getting the product down to the skin at the base of the feathers, focusing on the vent (Kentucky, UGA). For red mites, treating birds is not enough: treat the whole house — cracks, crevices, roosts, nest boxes, walls and litter (UC ANR, Kentucky).
Plan a second round. Most insecticides do not kill pest eggs (Kentucky, UGA), so a follow-up treatment catches the newly hatched generation. Kentucky suggests checking birds 7–10 days after treating for northern fowl mites and lice and re-treating as needed, and a red-mite follow-up in 5–6 days; UC ANR describes two bird treatments 5–7 days apart for northern fowl mites. Always use the interval on your product's label.
Clean first. UGA notes that clean facilities make pesticides most effective.
Don't rely on emptying the coop. Red mites can survive for months without feeding, so removing birds for a few days does not work (Kentucky). For northern fowl mites, UC ANR notes that keeping birds out of an infested facility for more than three weeks can give control, since adults survive only two to three weeks without a host.

Product classes named by extension

Class / active ingredient	What sources say
Permethrin (synthetic pyrethroid)	Quick knockdown, relatively long residual (Kentucky); dusts, sprays and hanging strips (UGA)
Pyrethrins	Quick knockdown, short residual; on birds for NFM and lice or in crevices for red mites (Kentucky). Pyrethrins and pyrethroids have low mammalian toxicity (UC ANR)
Carbaryl (carbamate)	5% dust on birds for NFM and lice, or on roosts and litter for red mites (Kentucky). Resistance to carbaryl reported in northern fowl mites in parts of California (UC ANR)
Tetrachlorvinphos (organophosphate)	Dusts or sprays for birds or nests (UGA). UC ANR reports malathion resistance among organophosphates
Pesticide resin strips	Continuous control near roosts; use only in high-risk months to slow resistance (UC ANR)

UC ANR recommends rotating between chemical classes to slow resistance, spraying birds from below as well as above, and avoiding contamination of feed, water and eggs. Kentucky notes that poultry insecticides are often not stocked at garden centers and are easier to find at farm-supply stores.

Prevention

Quarantine newcomers. Kentucky advises assuming purchased birds are infested and isolating them until treatment is complete.
Clean or discard transport crates after use (Kentucky).
Keep wild birds out of the coop and feed (Kentucky).
Inspect on a schedule rather than waiting for egg production to drop.

If laying has dropped and you have ruled out parasites, see how age affects laying and supplemental lighting.