Vicki, I had a massive infestation of red mite last summer - and I do mean
MASSIVE. In the heat of summer the numbers seemed to explode between one
visit to the hen house and the next one.

Due to a fox attack, I was down on hen numbers and only had to treat a
couple of hens, but in response to the mite infestation those poor girls
abandoned both houses and were trying to sleep outside in thier night yard
on a perch I'd put there so they could sun themselves.

I went into the main house and felt all these things crawling on me - they
were falling from the rafters and I also had them on my trouser legs. Yes,
they are supposed to be nocturnal but that didn't stop the nasty blighters
getting on my during a hot sunny morning. I thought they were baby spiders
but they weren't. Talk about a case of the screaming creeps! I walked
straight into the shower fully clothed (and wearing my watch) and stripped
under the running water.

But to the hens and what I did there - I don't like using chemicals anywhere
on this farm but after extensive reading on the subject in my poultry books
and magazines, I did the following:
1) dismantled second house entirely - still not replaced but will be.
2) raked out both yards and then swept bare earth with a broom - all
sweepings went to tip - did not compost any of it.
3) borrowed coop and put this in the day yard (which is about a quarter of
an acre so I could put the coop a long way from the old house) then took
hens out of night yard/night house at night and treated them using the light
from a torch with Pestene Powder (active ingredients Suplhur 50g/kg and
Rotenone 10g/kg). I'd also treated the hay in the nest of this coop with
the same powder and added fire ash in a big tub so they could dust bath and
added the Pestene Powder to that too. (Sally mentioned diatomaceous earth
and the ash acts like that, but for diatomaceous earth to be effective, it
has to be very fine and here it costs a small fortuen to buy - ash seems to
work). The hens went from looking miserable to looking good.
4) Blasted the remaining hen house with a pressure washer and left it to dry
for a couple of days.
5) Sprayed hen house (nooks, crannies, roof (inside and out), perches and
floor) with Malaban Wash (active ingredient Maldison at 200g/L). Sprayed
once then left for recommended period and repeated spray. Left hens out in
day yard overnighting in their coop for a few weeks.

It worked, but it took a lot of effort and was a stinking rotten, filthy
job. Better a bit of effort than my poor hens looking miserable and me
feeling that crawling on the skin.