How to Keep Rats and Mice Out of Your Chicken Coop This Winter

A little while back, we asked our weekly Talking Hens newsletter readers what was stopping them from getting backyard chooks. The most common answer was not foxes, not the neighbours, not even the Council, it was rodents. So if rats and mice are the thing holding you back, you are in good company, and the good news is that it is a very solvable problem.

Here is the part worth understanding first. Rats and mice do not hibernate. They stay active right throughout winter, adjusting their behaviour and seeking shelter, often much closer to us than people realise. Winter does not create rodents; it just concentrates the ones already lurking around into the warmest, best-fed spot they can find, and a chicken coop ticks every box. Catchmaster. 

Three things push them your way once the weather turns.

Heavy winter rain tends to flood and collapse their burrows, so they move to higher ground toward dry, sheltered structures like coops, sheds and woodpiles. Natural food gets scarce, so instead of roaming, they zero in on a reliable feed source, and an open feeder is about as reliable as it gets.

Cold, wet nights send them looking for insulated nooks and crannies to nest in. Mice in particular are less tolerant of the cold than rats, so they are more motivated to get somewhere warm. Breeding slows in the cold, but it never fully stops, and a warm nest with food on tap can support uninterrupted breeding straight through the season. A small problem in May can be a smelly, established one by August. Terminix.

They are not just a nuisance either. A rat eats roughly ten per cent of its body weight in food a day, fouls far more feed than it eats with droppings and urine, carries parasites and disease that put your flock and your family at risk, and will happily chew through timber, plastic, wiring and insulation. If at all possible, you do not want them setting up house.

How to tell they have found you

Do a slow lap at dusk with a torch and look for holes or burrows around the perimeter, fresh droppings along fence lines and on top of feed bins, a strong musky smell near the coop, gnaw marks on timber, and feed disappearing faster than your hens could possibly be eating it.

Seven practical ways to deter rodents this winter

1. Get the mesh right. This is the one most people get wrong. Standard chicken wire keeps your chooks in, it does nothing to keep rodents out. To stop rats, line the ceiling, walls, doors and the floor with heavy galvanised aviary mesh. With a dirt-floor run, many people bury the mesh or use an outward apron 20 to 30 cm wide around the perimeter. This will normally stop foxes, but not rodents. To stop mice, you need to go finer, around 6 mm, because a mouse can squeeze through a gap roughly the width of a pencil or biro. Worth the effort, because metal is one of the only things a rodent cannot (normally), chew through. Hobby Farms.
2. Seal any gaps that they are already using. On your nighttime reconnaissance, check around doors, under eaves and between cladding. Pack gaps with steel wool, then a rodent-resistant filler or mortar, and cap with a small section of mesh where you can. The rule of thumb is simple. If a pencil fits through the gap, a mouse can too. Pay particular attention to the eave area on corrugated roofs, where rodents can easily enter.
3. Store feed in airtight stainless steel bins. Rodents chew straight through feed bags and plastic tubs, and they can smell the contents from a fair way off. A sealed, food-grade stainless steel bin keeps the smell in and the teeth out. Keep it up off the ground on a small stand to reduce any condensation and make sweeping underneath it easier.
4. Switch to a treadle feeder. A good treadle feeder like the Chook-Tred opens under the weight of a hen but stays shut for anything lighter, so there is no free midnight buffet for rodents. Set the door tension correctly, sit it on a level surface, and close access overnight if you're starting out with an existing rodent problem.
5. No scraps left inside the chicken coop. Use a good stainless-steel scrap tray for treats, clear up any leftovers well before dusk, and tip the uneaten bits into a compost bin sited well away from the coop. Fewer floor calories means fewer night visitors.
6. Keep food out of the sleeping quarters. The coop is for sleeping and laying. Feeders belong in the run in a protected, dry location. Less spillage and smell inside means fewer reasons for anything to break in and contaminate the nests.
7. Tidy the surroundings. Shift woodpiles, stacked cardboard, long grass and open compost away from the coop. Keep the perimeter of the chicken coop clear so you can see what might be moving towards the coop. A deep-litter system with good quality, kiln-dried wood shavings helps, too, since it breaks down droppings into compost quickly and gives rodents and flies far less to work with.

A serious rethink on poison

If your instinct is to grab a box of rat bait, it is worth knowing that the rules have just changed. In March 2026, the APVMA suspended all second-generation anticoagulant rodenticides, the strong "one feed" baits, for a full year from 24 March 2026, and major retailers, including Bunnings, are pulling them from shelves, with Bunnings doing so by 30 June 2026. The reason matters. These poisons linger in a rodent's body, so they move up the food chain and kill the owls, boobooks, kookaburras, eagles and goannas that eat poisoned rats. Australian Pesticides and Veterinary Medicines Authority.

Even setting the law aside, poison was never a great fit around backyard chickens, or around the very owls that will hunt rats for you for free. So lean on the methods that work and avoid collateral damage. Snap traps set along walls and hard runs, baited with peanut butter and checked every morning, are simple and effective. If you must use any bait at all, it goes only in a locked, tamper-resistant bait station.

The bottom line

Rodents are chasing three things in winter. Food, warmth and shelter. Take away the easy feed, close the gaps with the right mesh, and keep the area open and tidy, and your coop turns into a poor prospect almost overnight. Your flock stays warm, healthy and a lot less interesting to anything with whiskers.

And if rodents were the thing keeping you from getting chooks in the first place, hopefully, this shows it is nothing a sensible setup cannot handle. We are always happy to talk it through.