Treating and Preventing Red Mite Infestations

Why Red Mite Matters More Than You Think

Red mite is one of the most common and frustrating problems in backyard flocks and smallholdings. The tiny mite, Dermanyssus gallinae, feeds on the blood of your hens, usually at night. It does not live on the bird itself but hides in the coop during the day, tucked into crevices, under perches and around nest boxes. A light infestation can go unnoticed for weeks. A heavy one can leave hens anaemic, pale-combed and reluctant to roost, with a sharp drop in egg production and sometimes weight loss. Mites also foul the coop with droppings and cast skins, and they can bite humans, leaving itchy red marks. In the UK, warm spells from late spring to early autumn are prime time for red mite, but heated coops and mild winters can keep them active year-round. The good news is that with regular inspection, thorough cleaning and careful treatment, you can keep them under control.

Know Your Enemy: Signs and Lifecycle

Adult red mites are tiny — roughly the size of a pinhead — and greyish-white until they feed, when they turn red or dark brown. They cluster in cracks, under perch ends, inside nest box joints, behind felt roofing and along any rough timber. In warm weather, the lifecycle from egg to adult can complete in as little as seven days, which is why an infestation can explode if you miss a weekly check. The mites can survive for months without a blood meal in cooler conditions, waiting for a new hen to arrive.

• Restless hens at dusk: birds may refuse to settle, peck at themselves or crowd the doorway rather than go inside.
• Pale combs and wattles: a sign of anaemia in heavy infestations.
• Dropping egg production: hens under stress often lay fewer or smaller eggs.
• Grey ash-like dust: mite clusters and cast skins in crevices.
• Red smears: squashed mites on perches, eggs or your hands after handling equipment.

Inspecting the Coop: Where to Look and When

Make inspection a habit at least once a month, and weekly through summer. Take a torch, a piece of white kitchen paper and a small scraper. Wipe the paper along the underside of perches, nest box lips, joints, screw holes, pop holes and roof edges. Red mite will show as grey smears or red streaks. Pay special attention to felt roofs, tongue-and-groove timber, hollow plastic sections and old second-hand coops. If you suspect mites but see none by day, check again at night with a torch — you may catch them crawling towards the hens. Always inspect new birds and second-hand equipment before they come near your flock.

• Under perch ends and brackets
• Nest box corners, undersides and hinges
• Roof felt, vents, window frames and door runners
• Droppings boards and tray runners
• Any cracks, splinters or lifted edges in timber

Cleaning and Clearing an Infestation

If you find red mite, act quickly and thoroughly. Move hens to a secure run or spare coop. Strip out all bedding, nesting material, feeders and drinkers. Bag and burn or bin the bedding — do not compost it near the coop. Scrape perches and surfaces, then vacuum crevices if you can, emptying the vacuum outside immediately. A steam cleaner is excellent for joints and perches because it kills mites and eggs without chemicals. Wash down with hot soapy water, rinse and allow to dry. Apply a poultry-safe red mite treatment to every crevice, not just flat surfaces. Repeat after five to seven days to catch newly hatched mites. If hens are itchy or visibly infested, use an approved poultry dust, following the label carefully for egg withdrawal periods. Do not return birds until treated surfaces are dry and safe.

Safe Treatments for Hens and Housing

Choose products licensed for poultry or approved for use around hens. Diatomaceous earth (food grade) can help in dry conditions, but it is a respiratory irritant, so wear a mask and avoid creating clouds of dust around birds. Many keepers use a licensed acaricide spray or powder for the coop, plus a poultry dust for the birds themselves. Always read the label, remove feed and water during treatment, ventilate well and observe withdrawal periods. Avoid DIY remedies such as diesel, engine oil or strong bleach residues — they harm hens and do not solve the problem. Sticky traps and corrugated cardboard traps can help monitor mite activity, but they will not cure an infestation. If the problem is severe or keeps returning, speak to your vet or an agricultural merchant for advice on suitable products.

Prevention: Routines That Keep Mites Away

Prevention is a mix of good design and steady routine. Keep the coop simple: removable perches, smooth surfaces and as few crevices as possible. Seal or paint bare timber where safe to do so. Clean weekly by scraping droppings, replacing soiled bedding and wiping perches. Do a deeper clean monthly, and treat any new or second-hand coop before use. Provide a dust bath with wood ash and a little diatomaceous earth, but do not overdo it. Keep wild birds out, control rodents and quarantine new birds for two to three weeks. In summer, inspect every week; in winter, check monthly. A healthy, well-fed hen copes better with mites, so keep stress low and nutrition good. Red mite is persistent, but with regular checks and prompt action, it is a problem you can manage without losing your flock’s health or your enjoyment of keeping hens.