Lice

In my decade-plus years of keeping chickens I have only ever seen lice twice – both times just on one bird, in small numbers and seemed to go away before I had to intervene. If you are checking your flock for external parasites you’ll be able to distinguish lice from mites: the latter are smaller, darker and slower. Lice are wingless, six-legged insects that live on both the skin and feathers of infested chickens. Good thing for us, they are species specific, meaning they live on poultry hosts and not people.

Like red mites, lice spend their entire life cycle on the body of their host, where they survive by eating feathers, dead skin, blood or sebaceous secretions. Chickens deal with getting rid of lice and mites by dust bathing and preening their feathers daily.

Lice infestations are more likely to happen when birds don’t have access to a year-round dust bath or are not able to preen themselves properly (e.g. crossbeaks, debeaked hens, and injured or sick birds). I live in a temperate rainforest – wet in winter, but hot and dry in the summer. That’s good for my birds, as lice prefer humid areas.

Molting season will deplete parasite populations as feathers are dropped.

How will you know if your birds have external parasites? Go out to your coop at night wearing a headlamp and check your birds one by one. Part their feathers around their vent, breast and thighs so you can see their skin underneath and look for egg clusters or feeding adult louse at the base of the feathers.

They are repelled by light; as you spread the bird’s feathers, they will usually scatter and hide. There are many species of lice, several that live on chickens. They vary in colour from off-white, yellow, tan and black with adults large enough to see with the naked eye.

Each variety lives on particular areas of the bird’s body and has devised different methods to avoid host preening. ‘Head lice’ live on the head where chickens can’t reach them; ‘wing lice’ hide between the barbs of feathers.

Lice have a life span of about a month. Each female louse lays 50-300 eggs (nits): whitish, oval capsules, which are cemented in clusters, or individually, to the base of the feathers or between the barbs of the bird’s feathers. The most common species found in small flocks, ‘body lice’ and ‘shaft lice’ are usually found around the vent, breast and thighs. Their eggs are found cemented in clusters to the base of the feathers, especially around the vent.

They hatch in 4-7 days and within two weeks reach maturity. Hatched eggs will remain attached to the feathers and appear grayish and flattened in appearance.

Treatment

The eggs are often easier to find then the lice, since the eggs will glisten in reflected light, particularly before they hatch. If you find lice on your birds, assume that all members might have them and treat the whole flock by removing the eggs, which are resistant to insecticides, and then treating your birds. To remove the eggs bathe your birds or coat them with a softener like NuStock. When using insecticides make sure they are effective against lice, and not just mites or fleas. Recommended sprays, dusting powders or topical applications include: Ivermectin, Elector PSP, pyrethrin, permethrin or Fipronil.

Prevention

• Don’t de-beak your birds as it impedes their ability to rid themselves of external parasites.
• Provide access to a year round dust bathing area.
• Clean your coop regularly.
• Two or three times a year do a thorough cleaning: hose/power wash the interior, including walls, nest boxes and roost bars.
• Dispose of dropped feathers and coop bedding where your birds don’t have access to them.
• Do monthly checks on your birds and look for lice and their eggs.
• Practice good biosecurity so that you don’t inadvertently bring parasites back home to your coop.
• Quarantine new birds.

I’m not very knowledgeable in the use of herbs to treat parasites, but there is clear evidence that many alternatives to insecticides are effective, including the use of turmeric and wormwood. This article provides more detailed information.