How do I know if my birds have lice? Menacanthus stramineus, identification, life cycle and major infestation periods.

Common poultry lice are parasites, they live on their host and therefore it would be self-defeating if, as individuals they were to cause harm to the creature on which they rely for their very survival. This is particularly pertinent for the louse, as it is host specific and moreover will die if stays too long off the bird. In this article I will share how to identify these lice and how to determine why and when they have reached significant population levels, so as to threaten the general well-being of your flock.

Our Chamois white-laced Polish Roosters and henBeauty and the beasties - Three of our Chamois White-laced Crested Polish awaiting inspection.

Close up of lice on a Polish roosterCaramel coloured shiny lice feeding at the base of Rufus' tail feathers. 
In the film below you will see how quickly they move once revealed!

Life cycle and lifestyle

Common poultry lice are ectoparasites, thus living on the skin. They are insects, with a short life span, which in adult form, is from 2 to 3 weeks. They arrive at maturity within a few days and are prolific egg layers (50 to 300 eggs). There whole life cycle from egg to adulthood can be spent on a single bird although they can and do move between them. As with many parasites, they actually have a symbiotic relationship with their host, clearing the skin of debris from feathers, dry skin scales and scabs. Lice have chewing-type mouth-parts, unlike mites for example, which have piercing ones for sucking blood. Lice will however, feed on blood, where it has already emerged from punctured skin or damaged feathers. In my experience, when in large numbers they can also cause dermatitis around these same areas. 

Egg clusters of the common poultry louse
 Clusters of lice eggs attached to Stanislas' vent feathers

My conclusions are therefore, that although fulfilling a function in the removal of dead skin and new feather casings, if they are present on your birds in numbers larger than the bird can deal with by itself, then the lice need to be dealt with speedily. The major advantage is that they are easily identified, mainly by the white clusters of eggs aka nits (pictured above). The females cement these around the base of the feather shafts. Furthermore, unlike some other poultry pests, the nymphs and adults are visible to the naked eye (1 to 3mm in length). 

Tell-tale signs that your birds have a lice problem

First indications your birds may have lice they are not coping with:
- your hens may go off lay, 
- in general, birds appear fatigued due to interrupted sleep patterns,
- damaged feathers, 
- sometimes but not always, birds have grubby feathers round the vent, 
- they appear cold due to damage and loss of fluffy down feathers.

Indications of important infestations: 
- birds seem listless and depressed, 
- they are excessively grooming themselves or other birds as they consume  the abundant lice. 
- When you pick your bird up the lice are so numerous and overcrowded, they instantly transfer on to you in search of a new host.

Organic chickens and fantails in a food forest
Peacefully entering into Autumn. Just coming out of the moult and growing new feathers

When should you be expecting this?

Essentially now at my time of writing this in August when the birds are coming out of moult and growing new feathers with all the resultant debris associated with this procedure. However, there are several forces which can bring a bird into a moult at any time of year, these include, changes in weather patterns, stress and heavy metal toxicity. Young birds also have differing patterns of moulting as they replace downy feathers as they grow bigger. Furthermore, if you experience heavy rains at any time of year this can affect the availability of dust-bathing sites for your birds and lead to a build-up of lice too.

Dust bathing in the greenhouse on a rainy day
A whole fluffy mass of dust-bathers in the greenhouse during the rainy season.

Which of my birds are most at risk?

The general physical health of a bird will affect whether or not he/she will be able to control his or her own lice population. An ill bird, in my experience, loses its will to preen long before it stops eating. Therefore, a lice infestation is also a good indication that a bird may be feeling unwell. Broken or damaged beaks or impaired eyesight will also impact on how well a bird preens itself, so if you have a bird with such a condition you should regularly check it for lice. On the emotional level, a bird with stress, depression or one which has recently lost a mate or sibling, can also be at risk from lice due to lack of preening.

Inspecting a Polish hen for lice
 Inspecting Garbo for 'little visitors' 

In conclusion

Lice in effect are providing a service for your birds of both a dedicated cleaner and also as extra protein in the form of a handy snack! However, when food for the louse is plentiful and opposition limited it starts to multiply at an alarming rate leading to an infestation, which can impact on a bird's general health. As a general rule I would inspect all, ill, depressed or stressed birds for lice as well as checking all birds during the moult and or any periods of wet weather. In the next article I will look at how to treat them if infested.

And now if you'd like to, sit back and watch the film:

If you have any questions, observations or comments, please feel free to leave them below and if you found this article useful, then think about sharing it.

You can find Part 2 - Treatment with essential oils and prevention through diet here

All the very best,
© 2014 Sue Cross

1 comment:

  1. Hi Sue, I think I have watched all your videos on YouTube. Thank you for making them. I have some chickens, different breeds and now noticed that thay have lice-at least it looks like lice. But it's a strange lice as it stays only on thde head of my chickens. I have tried searching on Internet but all treatments are for normal lice...

    My 2 serama hens have them-one really a lot, and few sultan crosses. I'm not sure how to deal with it. I have sprinkled some DE on their heads carefully but one serama has thousands of tiny eggs attached to her feathers on the head. And I can't find a way of removing them so they dont hatch on her. Should I just let them hatch and sprinkle more DE or maybe there is a different way? Thank you. Aga