How to Keep Weasels & Mink Out of a Chicken Coop

By John Walker · Backyard chicken keeper in Dallas, Texas since 2017

Weasels and mink are the hardest predators to keep out of a chicken coop, because they can squeeze through a gap barely an inch wide and they kill far more birds than they eat. The defence is not a rooster or a trap — it is a coop sealed with half-inch hardware cloth, every gap closed, and a pop door that locks every night. Get the sealing right and weasels cannot get in; get it wrong by a single gap and you can lose the whole flock in one night.

How to keep weasels and mink out of a chicken coop

Keep weasels and mink out of a chicken coop by sealing every opening larger than half an inch with half-inch hardware cloth, closing all gaps around doors, vents and the roof line, and locking the pop door every single night.

Weasels can squeeze through a hole as small as one inch across, and mink through a hole of about one and a half inches, so chicken wire and gaps you can barely see are no barrier at all. The only reliable defence is a coop that is sealed like a box.

Weasels and mink are mustelids — small, long-bodied, powerful hunters that hunt at night and kill by biting the back of the neck. They are worse than most predators because they do not stop at one bird: a weasel in a coop will often kill every bird in it, drinking blood and eating little, in what looks like a frenzy. Keepers who find a coop full of dead birds with small bites to the neck have usually had a weasel visit.

Trapping and roosters do not solve the problem. A rooster is asleep when a weasel hunts, and trapping one weasel does not stop the next. The answer is to make the coop weasel-proof, and this guide covers every part of that job: the mesh, the gaps, the floor, the pop door and the run.

Why weasels and mink are different from other predators

Weasels and mink are different from other predators because of their size, and that size changes everything about how you defend the coop. A fox needs a hole the size of a dinner plate; a weasel needs a hole the size of a coin.

That means the gaps that do not matter for other predators — a loose board, a gap under the roof, a vent covered with chicken wire, a hole where a pipe enters the coop — are open doors for a weasel. Most coops that are fox-proof are not weasel-proof.

They are also strong for their size. A weasel can climb a vertical wall, squeeze under a door, and chew through thin wood and plastic. Mink, which are larger and semi-aquatic, are common near streams, ponds and wetlands, and they are bolder than weasels, sometimes hunting in daylight. Both are active all year, including in winter, when other predators are less active and food is scarcer.

Finally, they kill more than they need. A fox takes a bird and leaves; a weasel in a coop full of sleeping birds kills bird after bird, often leaving the bodies piled up with bites to the neck and the heads removed. That pattern — many dead birds, small neck wounds, little eaten — is the signature of a mustelid attack, and it is why weasel-proofing matters even in areas where you have never seen one.

Half-inch hardware cloth: the only mesh that works

Half-inch hardware cloth is the only mesh that keeps weasels out, and it is the first thing to buy when you weasel-proof a coop. It is welded wire mesh with half-inch square openings, made from galvanised steel, and it is the standard for predator-proof coops.

Chicken wire — the hexagonal mesh most people think of — has openings of an inch or more and is thin enough for a weasel to push through or a raccoon to tear apart. It keeps chickens in; it does not keep predators out.

Use 19-gauge or heavier hardware cloth, and fix it with screws and washers, not staples. Staples pull out under pressure, and a weasel or raccoon pushing against a stapled panel can work it loose. Screws with wide washers, spaced every few inches, hold the mesh firmly and cannot be pulled out. Overlap the edges of the mesh by a few inches at joins, and screw through the overlap.

Cover every opening with it: windows, vents, the gap under the eaves, and the whole run. If the run is built from chicken wire, replace it or cover it with hardware cloth — a run that is half hardware cloth and half chicken wire is a run with a weasel-sized hole in it. Check the mesh every month for rust, damage or loose fixings, because a single failed panel undoes the whole job.

Sealing the gaps: doors, vents, roof and floor

Walk around the coop with a torch at night and look for light leaking out — every point of light is a gap a weasel can use. Pay attention to the corners where walls meet, the join between the wall and the roof, the edges of the pop door, and any place a pipe, wire or cable enters the coop.

A gap you can fit a finger into is a gap a weasel can fit through.

Doors are the most common entry point. A pop door that does not close flush, or that leaves a gap at the sides, is an open invitation. Fit the door so it sits flat against the frame, add a strip of timber or rubber draught excluder around the edges, and fit a latch that locks — a sliding bolt or a carabiner, not a simple hook, because raccoons can open hooks. An automatic pop door that closes at dusk and locks is the best option if you cannot always be there at night.

The floor matters too. A coop with a dirt floor needs a wire apron buried around the outside, or a sheet of hardware cloth under the floor, because weasels dig. A coop with a solid wooden or concrete floor is safer, but check for gaps where the floor meets the walls. And check the roof line: a gap under the eaves is a classic weasel entry, and it is easy to miss because it is above eye level.

The run and the apron

The run needs the same treatment as the coop. Cover the whole run in half-inch hardware cloth, including the roof, because weasels climb and mink can come over the top. A run with an open top is a run that is open to every climbing predator, and netting that stops a hawk will not stop a weasel.

Add a wire apron around the run: a strip of hardware cloth laid flat on the ground, extending 18 to 24 inches out from the base of the run walls, and pinned down with tent pegs or buried under a few inches of soil. A digging predator hits the apron and cannot get under the wall. Burying the wire vertically also works, but the flat apron is easier to install and just as effective.

Keep the area around the run clear. Long grass, woodpiles and compost heaps next to the run give weasels cover to approach unseen, and they give rats somewhere to live — and rats attract weasels. A clear strip of short grass or gravel around the coop makes any predator visible, and it makes the apron easier to inspect.

What to do after a weasel attack

If you find dead birds with small bites to the neck and little eaten, assume a weasel or mink got in, and act the same day. Move the surviving birds to a secure place — a garage, a shed, or a friend’s coop — and do not put them back until the coop is sealed.

A weasel that has found food will come back the next night, and it will come back until the food is gone.

Find the entry point. Look for a gap, a hole, or a panel that has been pushed in, and check the ground for tracks: weasel tracks are small, with five toes, and often show a bounding pattern with pairs of prints. Fix the gap properly, with hardware cloth and screws, not with a board nailed over it — a weasel will find the next gap, and a board is a temporary fix that hides the problem.

Consider trapping as a short-term measure, but check your local rules first: in many places, trapping weasels and mink is regulated, and relocated animals often return or die. Trapping is not a substitute for sealing the coop. The birds are only safe when the coop is sealed, and no amount of trapping makes an unsealed coop safe. Our guide on predator-proofing a chicken coop covers the full checklist for all predators, and the guide on how to predator-proof a chicken run covers the run in detail.

Do deterrents work against weasels?

Most deterrents do not work against weasels. Lights, radios, ultrasonic devices and predator urine have little effect on a mustelid that is hungry and has found a coop full of birds. A motion-activated light may startle a weasel once, but it will not stop it coming back.

Scent deterrents wash away in the rain and need constant reapplying.

Livestock guardian dogs can help on larger properties, because a dog that patrols at night will catch or deter a weasel. But a dog is a major commitment, and it is not a practical answer for a backyard flock. Geese, which are sometimes suggested as guards, are no use against a weasel at all.

The honest answer is that the only deterrent that works is a sealed coop. Spend the money on hardware cloth, screws and a good latch, and spend the time on finding and closing every gap. That is the whole strategy, and it is the strategy that works.

Sources: predator-proofing guidance on this page follows the poultry housing pages at poultry.extension.org and the University of Minnesota Extension.

Related tools and guides

For more on the same topic, see Predator-Proofing a Chicken Coop and How to Predator-Proof a Chicken Run.

Frequently asked questions