Chickens
Red mite
Also known as: red mite, poultry mite
A tiny blood-sucking parasite that hides in coop cracks by day and feeds on chickens at night — the most common pest of backyard hens, worst in warm months.
Red mite (Dermanyssus gallinae) is the bane of UK chicken keepers. Despite the name, a hungry mite is grey or off-white; it only turns red once it has fed on your birds' blood. It is a parasite of the coop rather than the bird — it lives in the woodwork, not on the hen.
The lifecycle that makes them so hard to beat
Red mite are nocturnal. By day they hide in cracks, in the ends of perches, under roofing felt and in the dark corners of nest boxes. At night they creep out, feed on roosting birds, then retreat before dawn. This is why you can own infested hens and never see a mite on them in daylight.
In warm conditions a mite can complete its lifecycle in under a week, so a handful in June becomes thousands by July. They can also survive many months without a meal, sitting empty in the coop waiting for hens to return.
Signs to look for
- Tiny grey or red specks, and greyish ash-like deposits, clustered in crevices and along the underside of perches.
- Pale combs and wattles, and listless, lethargic birds (the blood loss causes anaemia).
- Hens reluctant to go into the coop at dusk, or roosting on the ramp or in the run to avoid being bitten.
- A noticeable drop in laying, and sometimes blood spotting on eggs.
Heavy infestations weaken birds badly and can even prove fatal, so they are worth catching early — especially if you have young birds just coming up to point of lay or a hen sitting tight while broody, as both spend long stretches in the coop.
Why UK summers are the danger zone
Red mite thrive in warmth. Through a British winter the cold keeps them dormant and numbers stay low, but from May onwards, as nights warm up, populations can rocket. Check weekly from late spring to early autumn — it is far easier to stop an outbreak starting than to clear an established one.
How to control them
Control is mostly about cleaning, not spraying the birds. Strip the coop right out, scrub it, and pay attention to the joints and crevices where mites shelter; a pressure washer or a steam cleaner reaches what a brush cannot. Once dry, dust the perches, crevices and nest boxes with food-grade diatomaceous earth, a fine mineral powder that scratches the mites' waxy coat so they dry out. Repeat treatments every few days to catch newly hatched mites.
Wooden coops give mites endless hiding places, so plastic coops are far easier to clean and far less hospitable — many keepers switch to plastic precisely because of red mite. Whatever your coop, regular inspection through the warm months is the real defence.
In a UK garden
In the UK red mite explodes from late spring through summer, when warm nights let numbers double in a matter of days, then goes quiet over a cold winter.
Example
Wipe a white tissue along the underside of a perch after dark — if it comes away smeared with red streaks, those are squashed, blood-fed mites.