How to Fox-Proof a Chicken Coop

Foxes are the biggest threat to a backyard flock, and the RSPCA's advice is blunt: build the coop with strong, meshed fencing at least 6ft tall, sloping outwards, to stop foxes climbing over it¹. Chicken wire is not enough, because foxes can chew through it. Stop them digging under by running the fence a foot into the ground, or by laying a mesh skirt 40cm wide flat on the ground with bricks or large stones on top¹. And lock the birds in the coop at night, because foxes are nocturnal¹.

That is the core of it. The rest is routine: check the fence and the hen house regularly, keep feed stored away from rats and mice, and remember that hungry foxes are more daring and determined in winter². A coop that is secure on the night you build it can be undermined by a loose panel, a gap under a gate or a latch a fox can nudge open within weeks.

This page covers the two places your flock has to be safe, the coop and the run, how to manage hens that spend more time shut in, and what to do about sick or dead birds while the UK's bird flu prevention zone is in force. For the wider picture of housing, feeding and the law, see Keeping Chickens: Housing, Feeding and the Law.

Start with a healthy flock: watch the birds before you buy

A fox-proof coop protects birds that are worth protecting, so begin with healthy stock. Before you pick individual hens, watch the whole flock for a few minutes: a flock that has a couple of sickly birds is likely to have a disease or parasite problem⁵. Buying from a source with an obvious problem simply imports it into your garden.

Once birds are home, monitor the flock for signs of illness and isolate any sick bird immediately⁶. Isolation protects the rest and lets you watch the poorly bird closely. Keep the coop clean, because red mites are found under the wings or living in coops, particularly wooden ones, and are more commonly seen in summer; a plastic coop is worth considering because red mites struggle to settle in plastic⁴. Chickens kept on the same outdoor ground for more than a month need regular worming, and birds with worms should be moved to fresh grazing to avoid reinfection from infested droppings⁴.

If you are adding to an existing flock, introductions need care. Start with a "see but no touch" arrangement, which also acts as quarantine, and let the birds share the same space for short periods over a few days at dusk before merging them fully. Separate them if bullying breaks the skin⁴. In summer, covering the coop windows with black plastic stops bullying starting before you are up⁴. There is more detail in How to Introduce New Hens to an Existing Flock.

A healthy flock is also easier to keep secure, because birds that feel safe roost early and settle. Perches should be around 3 to 5cm wide with rounded edges, with 15cm of roosting space per chicken, and a height of 40cm lets chickens feel safe and helps prevent pecking⁴. Enough perch space for every bird means none is left on the floor, where a fox that gets in will find it first.

The coop and the run: the two places your flock needs to be secure

Think of security in two layers. The coop is the night box, and the run is the daytime exercise yard. A fox that cannot get into either cannot take a bird, but a weakness in either one is enough.

For the run, the RSPCA's specification is the one to build to: strong, meshed fencing at least 6ft tall, sloping outwards, to stop foxes climbing over it¹. Chicken wire will not always keep predators and rodents out of runs, and welded mesh is a better alternative¹. To stop digging, install the fencing a foot into the ground, or place a mesh-skirt around the base of the coop, flat on the ground at a width of 40cm, with bricks or large stones on top¹.

For the coop itself, the house must provide protection from vermin such as foxes, rats and mice, and you may need to be able to padlock it⁷. Keep the feed bin secure inside the hen house or a shed or garage to prevent access by wild birds and vermin, and control rodents, which can be a threat to hens⁸.

Be realistic about what a bought coop promises. The makers of the Dorset Chicken Coop say it is made with thicker, sturdier wood, wire and locks, but that they cannot absolutely guarantee foxes and other predators won't try and target them⁹. The Dorset Coop & Double Run is described in the same terms, with fox safety not absolutely guaranteed¹⁰. That is not a reason to avoid a well-made coop; it is a reason to check it yourself and to add the ground defence and the night lock.

Runs without grass: woodchip and bare ground

A secure run often ends up without grass, because hens scratch and eat it off. That is normal, but it changes what the run needs. Bare ground gets muddy and holds droppings, which raises the worm burden, so birds kept on the same outdoor area for more than a month need regular worming and a move to fresh ground to prevent reinfection⁴.

Woodchip gives the flock something to scratch in and keeps them off mud. Whatever the surface, the run has to be big enough. Some wooden coops come with a small run attached which are not suitable for chickens, as they need much more space¹¹. A small attached run is fine as a shelter or a temporary pen, not as the birds' only outdoor space. For how much room to allow, see How Much Coop and Run Space Do Hens Need?.

If you buy a wooden coop or run, note that it is supplied with a base coat of preservative, which provides initial protection against rot and insect attack¹². That is a starting point, not a permanent finish: re-treat it as the maker advises, and check the timber for soft spots, because rot opens gaps that a fox will find.

A covered section of run pays for itself in a wet winter. It keeps the ground drier, gives the birds somewhere to shelter, and means the run is usable when the weather is poor. Keep the surface turned over and topped up, and clear droppings regularly.

Feeding a shut-in flock safely: grit, winter rations and no kitchen scraps

Hens that spend more time in the run depend on you for everything. Choose a complete food rather than a mixed one, so the feed contains all the necessary nutrients, and store it in a cool, secure and dry place to prevent it going off or spoiling⁴. A secure bin also keeps rats and mice out, which matters more in winter when rodents look for easy food.

Grit is not optional. Chickens have no teeth, so they need insoluble grit such as hard flint grit to grind and digest food. Oyster shell is a soluble grit that provides extra calcium, particularly important for laying hens for stronger eggshells⁴. Offer both separately and let the birds help themselves.

Winter changes the ration. Chickens eat more in colder months to generate body heat⁴, so keep feed available and watch that the flock is getting its share rather than being bullied off the feeder. They also sleep more in winter to conserve energy and are generally less active during the day⁴, which means less scratching and more dependence on what you provide.

Cold weather brings a second fox risk. Store food safely away from rats and mice, especially at night, and regularly check fences and hen house security, as hungry foxes are more daring and determined in winter². The same pattern shows in advice for other outdoor pets: in winter foxes and badgers get hungrier and bolder, so hutches need to be sturdy enough to survive the attention of a determined predator¹³. Treat the darker months as the time to walk the fence line weekly.

Sick or dead birds: don't handle them while the bird flu prevention zone is in place

An Avian Influenza Prevention Zone is currently in place across the UK, and the RSPCA's advice is clear: don't touch or handle sick or dead birds. If you have to, thoroughly wash your hands immediately afterwards, keeping them away from your face or food⁴.

The prevention zone also sets out precautions for all poultry keepers, including pet hen keepers: cleansing and disinfecting equipment, vehicles and footwear; storing feed, water and bedding undercover; effective vermin control; keeping birds in a fenced-off area so they cannot access standing water; regularly disinfecting the coop and run; and discouraging wild birds from entering the area¹⁴. These are practical jobs, and most of them also help against foxes, because a tidy, fenced, vermin-controlled run is harder for any predator to exploit.

If avian influenza is confirmed in poultry or other captive birds, official control zones follow: a 3km protection zone and a 10km surveillance zone, or a 3km captive bird (monitoring) controlled zone¹⁵. In all disease control zones you must follow biosecurity rules, keep a record of anyone who transports or markets poultry or poultry eggs (with exemptions for table eggs), follow the rules for fresh meat, comply with biosecurity rules imposed by a veterinary inspector, not organise or attend bird gatherings, and not release game birds¹⁵.

For dead wild birds, arrangements differ by nation. In Northern Ireland, report dead wild birds, including swans, geese, ducks and gulls, using the DAERA Dead Wild Bird online reporting tool¹⁶. The same reporting route is set out in Northern Ireland public health guidance¹⁷. Do not handle the carcass while reporting it.

Heatstroke in an enclosed run and when to call a vet

A secure run can become too hot. Hens cannot sweat, and a covered, enclosed run with little shade traps heat in summer. Watch for the signs: open mouth breathing, wings and legs outstretched, reduced appetite and egg production, and staggering or falling over¹⁸. These symptoms can also indicate other health issues, so if heatstroke is suspected, call a poultry-friendly vet immediately for advice¹⁸.

While you wait, do what you can to cool the bird and the run: shade, ventilation and cool water. The principle vets apply to other animals is the same one to hold in mind: cool first, transport second¹⁹. For rabbits and rodents the RSPCA advises moving the animal to a cool, shaded place, wrapping it in a cool, damp towel and phoning the vet immediately²⁰. Never plunge an overheated animal into cold water.

Prevention is simpler than treatment. Site the run so it has shade for part of the day, keep water fresh and available, and avoid shutting birds into a small, unventilated space in a heatwave. The Met Office's weather-ready advice is a useful prompt to plan ahead for extreme heat and cold rather than react²¹.

For general hen health, including mites, lice and worms, see Chicken Health: Mites, Lice, Worms and Common Illnesses. If you are bringing home rescue birds, the arrival checklist at Checklist for Bringing Home Rescue Hens sets out what to have ready before they arrive.