War on Red Mite

2 of our hen houses have an infestation of red mite, a blood sucking parasite that, if left unchecked, can drastically reduce egg production and even cause death in chickens.  In previous years I have managed to just keep on top of it using a time consuming method of manually killing them but this year I really wanted to get totally kill them in an easier way ... which I hope I finally have done.

What are Red Mite?

These are not the harmless red spider mite that you can find in the garden but are 1mm long mites that live on chickens.  Females lay eggs which hatch into larvae that moult into first protonymphs, then deutonymphs before a final moult to become as adult.  Both nymph stages and the adults feed on chickens.  The total life cycle takes 7-10 days and adult mites can live 8-10 months without food, waiting for a new chicken host to appear.

Image from University of Florida

Effects on chickens

Even a minor infestation can have a very negative effect on a flock getting increasingly worse as numbers rise:  Effects can include:

• Chickens being unsettled 
• Fall in egg production
• Spread of diseases such as Newcastle Fowl Disease 
• Lesions on the chickens
• Death due to blood loss and/or anaemia

How to recognise an infestation

Red mite rarely feed in the day time so will leave the roosting chicken before dawn to hide in places such as cracks in the wood, behind nest boxes, under dried faeces, in cobwebs, between bricks etc.  Even when you think you have found every possible place they can hide they will find somewhere else.  Adults will, however, often be visible as a red mass in their preferred hiding place but larvae and nymphs are harder to find.  If you run a finger or white cloth under the perches it will come out red where you squash them.

At night you will see the adults moving along the perches and walls.  Look carefully and you may also see masses of tiny larvae and protonymphs swarming over walls, floors etc.

At night the chickens will be scratching a lot but in then case of a bad infestation your birds may well refuse to go into roost at night.

Red Mite Elimination

Red mite are difficult to get rid of.  There are various chemical products that you can chose but the mites can build up immunity to these.  They are also not permitted if you are raising organic chickens.

Spreading the ends of the perches with Vaseline which traps the mites can help but in large houses or those with many mite hiding place this is not practical.

If you can find where the mites are hiding, blasting them with a blow torch can successfully kill them (you will know you are killing them as you will hear a slight crackling or popping).  Again though, if your house is big or has many hiding places you may well not get them all.

Diatomaceous Earth - This has been my life saver.  I have been able to get reduce numbers with a combination of Vaseline and blow torching but never quite managed to get totally mite-free.  Diatomaceous Earth is the fossilised remains of diatoms which you buy as a slightly coarse powder.  It is harmless to humans and chickens but when the mites pass over it, for them it is like walking on razor blades.  It cuts into them causing them to dry out and die.  By spreading Diatomaceous Earth over all the perches and in all cracks etc my red mite numbers are greatly diminished and the houses will hopefully soon be pest free.  I have also given some to the hens as a dust bath helping to remove any mites still on them in the day time.

Preventing a red mite infestation

However good you chicken husbandry is, you are always at risk from wild birds or a new hen bringing the mites to your flock.  However you can reduce the likelihood of both getting an infestation or having it get to dangerous levels:

• Regularly check your hen house for signs on red mite so you can act quickly as soon as they are spotted.  If the hens go off lay in mid summer unexpectedly, expect the worst.
• Spread Diatomaceous Earth in the hen house and offer it as a dust bath to your flock
• Keep the hen house clean and cobweb free 
• Keep possible hiding places to a minimum - our perches are made from pallets so have loads of potential hiding places so we will renew these soon.

Remember though that the only way you can starve the red mite to death is to keep your hen house empty of birds for at least 10 months as this is how long the adults and deutonymphs can survive without food.

Have you had red mite infest your chickens and is so, how did you manage to get rid of hem?