HealthNote 2
Red mite, the third summer, and what I had been missing
In July 2024 the hens started standing about in the run at dusk instead of going in. I spent four evenings convinced something was wrong with the ramp before I took a perch out and looked at the end of it in daylight.
- Went up9 July 2024
- Redone21 June 2025
- Reading timeAbout 7 minutes
- GardenSheffield, South Yorkshire
The signs I misread first
The first sign was behavioural and I read it as stubbornness. Hens that have gone in at last light every evening for two years suddenly hanging about by the door, then roosting on the run frame in the rain, is not a preference. It is birds telling you that the place they sleep has become unpleasant. I checked the ramp, moved the ramp, cleaned the ramp, and wasted the best part of a week on it.
The second sign was in the eggs, and I only found it going back through the tally sheet afterwards. Weekly collection had drifted from around thirty to twenty-four without a single day that looked like a drop. Two of the birds had pale combs by the end of the month, and one of them, the smallest, was noticeably light when I picked her up. A heavy mite population takes blood from birds every night, and the cost of that shows up slowly in a way that a weekly tally catches and daily impressions do not.
Where they actually live
The thing I had wrong was the idea that mite lives on hens. It does not. It lives in the structure, in the crack behind a batten, in the socket a perch sits in, under the lip of a nest box, in the joint between two bits of board. It comes out at night, feeds for a short while, and goes back into the wood before morning. That is why a hen inspected at eleven in the morning looks perfectly clean and the coop is still full of them.
When I finally lifted a perch and carried it out into the sun, the two ends looked as if someone had blown cigarette ash into the sockets. Tapping it onto a sheet of white paper turned the grey dust into hundreds of moving specks. That was the moment the previous fortnight made sense. I had been treating the birds, twice, with a dusting powder, and achieving almost nothing, because six hens were the only clean surface in the whole structure.
Six weeks of treating the woodwork
What worked was tedious rather than clever. Everything removable came out: perches, nest boxes, droppings board, bedding. The bedding went in a bag and out of the garden the same morning rather than onto the compost heap two metres from the coop, which is what I did the first time and which achieved nothing at all. Then the inside got scraped, brushed out into a bucket, and gone over seam by seam. A pressure washer helped on the outside panels and was a mistake inside, because it drove water into joints that then took three days to dry.
After that it was a repeated cycle rather than a single treatment. I went over every joint, socket and seam, let it dry properly, then did the same again seven days later, and again seven days after that. The interval is the whole point: eggs already in the woodwork hatch over the following week, so a single thorough clean just resets the clock. Three passes at weekly intervals, in a July that was warm enough to dry the shed out between them, got the perch sockets clean. I kept a white cloth wedged under one perch end overnight as a test, because it shows specks that I would not otherwise see.
What I do now, every week, between May and September
Once a week through the warm months, the perches come out and get looked at end-on in daylight. It takes about three minutes and it is the only reliable early warning I have found. In the same round I run a finger along the underside of the nest box lip and check the two battens that hold the droppings board, because those are the three places it has ever started in this shed.
The structural lesson was about smooth surfaces. Where I could, I filled seams and took the sharp internal corners out of the design, so there are fewer places for anything to sit behind. Removable everything matters more than the material: a perch that lifts out in ten seconds gets checked weekly, and a perch that is screwed into a bracket gets checked when there is already a problem. The weekly egg tally recovered from twenty-four to thirty-one over about five weeks, and the light bird put her weight back on by the end of August.
The part I got wrong twice
In the first bad summer I treated the birds and not the building, and in the second I treated the building but composted the bedding at the bottom of the same garden, ten paces from the coop. Both times I thought I had dealt with it and both times it came back within a month. Mite does not need much to survive a cool fortnight, and a heap of warm bedding is a better home than the shed.
The other thing I would tell myself in 2024 is that the fortnight I spent worrying about the ramp was not wasted time because I was stupid. It was wasted because I was looking at the hens instead of at the wood. Hens are the visible part of the system and almost never the part that has gone wrong. Since I started checking perch ends every week, the worst I have found is a small patch in a nest box corner in June 2025, caught early enough that one clean and one follow-up seven days later ended it.
Counts come off the sheet on the shed door, weights off a kitchen scale, and the dates are the ones the thing actually happened rather than the day I got round to typing it up. This note was last corrected on 21 Jun 2025.