Mice enter chicken coops through gaps, feed spills, and nesting materials—and they compete with your birds for food while spreading disease

Mice are attracted to chicken coops because they find warmth, shelter, and a steady food supply. A single mouse can squeeze through a hole the size of a dime, so even small gaps in walls, doors, and ventilation become entry points. Once inside, mice eat chicken feed, contaminate water with their droppings, and can spread diseases like salmonella to your flock. The good news is that prevention works better than trapping: seal entry points, remove food sources, and reduce hiding spots, and you will see far fewer mice.

The most effective approach combines three actions: blocking their way in, removing what attracts them, and making the coop less comfortable to live in. You do not need expensive equipment—most of what works costs little and uses materials you may already have.

Key Takeaways

  • Mice can enter through holes smaller than a dime, so inspect your coop for gaps around doors, windows, vents, and where pipes enter the structure.
  • Store chicken feed in metal containers with tight-fitting lids, and sweep up spilled grain daily, because loose feed is the main reason mice stay in a coop.
  • Remove bedding and nesting materials that mice can shred and use to build nests, and keep the coop floor clear of clutter where mice can hide.
  • Seal entry points with hardware cloth (a metal mesh), steel wool, or caulk—materials mice cannot chew through—rather than relying on wood or plastic alone.

Seal gaps and holes where mice can enter

Walk around your coop in daylight and look for any opening larger than a pencil eraser. Check the base where the coop meets the ground, the corners where walls join, gaps around the door frame, spaces where the roof meets the walls, and any holes where electrical lines or water pipes pass through. Mice can flatten their bodies and squeeze through surprisingly small spaces, so do not assume a gap is too narrow.

Use hardware cloth (a metal mesh with openings no larger than 1/4 inch) to cover larger holes. Cut a piece slightly larger than the hole, hold it in place, and nail or screw it down around all edges. For smaller gaps, pack steel wool tightly into the space—mice will not chew through it the way they will through plastic or foam. Seal over the steel wool with exterior caulk to hold it in place and block drafts. For gaps around door frames, install a door sweep or threshold that closes the gap when the door is shut.

Check your work by trying to push a pencil through any sealed area. If the pencil goes through, the gap is still large enough for a mouse. Pay special attention to the corners of wooden coops, where wood shrinks and warps over time, creating new gaps.

Store feed in metal containers and clean up spills when ready

Chicken feed is the main reason mice move into a coop and stay there. A metal trash can with a tight-fitting lid is the simplest solution—it keeps feed dry, prevents mice from accessing it, and lasts for years. Avoid plastic containers, which mice can chew through, and never leave feed in open bags. If you use a large metal can, drill a small hole in the lid and install a hinged flap so you can scoop feed without removing the entire lid.

Sweep the coop floor at least once a day, paying special attention to corners and under roosting bars where feed accumulates. Even a handful of scattered grain will feed a mouse for days. If you feed your chickens outside the coop, do not leave uneaten food sitting on the ground—remove it after 30 minutes. Mice will also eat spilled water, so check waterers for leaks and fix them promptly.

Feed your chickens only what they will eat in one sitting. Overfeeding creates waste, and waste attracts mice. A good rule is to offer feed in the morning and again in the afternoon, removing any leftover grain before dusk when mice become active.

Remove bedding and nesting materials mice can use

Mice shred soft materials like straw, hay, and wood shavings to build nests. While your chickens need bedding for comfort and dust baths, you can reduce the material mice have access to by using coarser bedding and removing old, soiled bedding more often. Sand is an excellent alternative because mice cannot easily shred it, and it drains well and controls odor.

Do not store extra straw or hay inside the coop or in attached storage areas. Keep bedding supplies in a separate shed or garage in sealed containers. If you must store some bedding near the coop, keep it in a metal bin with a lid, away from the coop entrance.

Clean out the coop completely at least once a month, removing all old bedding and replacing it with fresh material. This removes mouse nests before they become established and gives you a chance to inspect the coop floor and walls for new gaps or damage.

Remove clutter and hiding spots inside and around the coop

Mice need places to hide during the day. Inside the coop, remove or elevate anything that creates a dark space: old equipment, stacked wood, cardboard boxes, or piles of tools. Keep the area under roosting bars clear so you can see the floor. Outside the coop, trim grass and weeds within 3 feet of the structure—mice use tall vegetation as cover when moving between the coop and their burrows.

Move firewood piles, compost bins, and stored materials at least 10 feet away from the coop. These are common mouse habitats, and the closer they are, the more likely mice are to explore your coop. If you have a compost pile, use a bin with a find lid and avoid composting meat, bones, or chicken feed.

Stack any equipment or supplies outside the coop on shelves or pallets at least 12 inches off the ground. Mice will not cross open space to reach something, so elevating items makes them less attractive as shelter.

Use traps and bait stations as a backup, not a first step

Once you have sealed entry points and removed food sources, traps become much more effective because hungry mice are more likely to take bait. Snap traps and electronic traps kill quickly and are safer around chickens than poison, which can harm birds if they eat a dead mouse. Place traps along the walls where mice travel, not in the middle of the floor.

Bait stations are plastic boxes that hold poison or bait inside, with small openings that mice can enter but chickens cannot. If you use poison, place stations outside the coop, at least 10 feet away, and check them weekly. Never use poison inside the coop where a chicken might peck at it or eat a poisoned mouse.

Check traps daily and dispose of dead mice in a sealed bag in the trash. Wear gloves when handling traps or dead mice to avoid contact with bacteria. If you catch mice regularly even after sealing gaps and removing food, you likely have an entry point you missed—go back and inspect the coop again, paying special attention to the base and corners.

Inspect your coop monthly and repair damage promptly

Wooden coops develop new gaps as wood shrinks, warps, and rots. Metal coops can rust and develop holes. Check your coop at least once a month, especially before winter when mice are most active. Look for new gaps, damage to hardware cloth, loose door frames, and areas where the coop has settled unevenly.

Repair damage when ready rather than waiting for a convenient time. A small gap that you plan to fix "next month" becomes a highway for mice. Keep supplies on hand: hardware cloth, steel wool, exterior caulk, and nails or screws. If you find rot in wooden walls, cut out the damaged section and patch it with new wood and hardware cloth.

After heavy rain or snow, check for new leaks or damage. Winter is the season when mice are most desperate for shelter and food, so fall is the best time to do a thorough inspection and seal any gaps you find.

Frequently Asked Questions

Will my chickens get sick if they eat a mouse?

Chickens will eat mice if they catch them, and this is generally safe. However, if a mouse has eaten poison, the chicken could be harmed. This is why poison should only be used outside the coop, in bait stations chickens cannot access. Live traps or snap traps inside the coop are safer.

Do cats or other predators help control mice in the coop?

Cats and barn owls are excellent mouse hunters, but they also hunt chickens. A cat may coexist peacefully with chickens if raised with them from a young age, but this is not may provide. Owls and hawks will kill chickens, so predator control is not a reliable solution for mice.

What is the best bedding to use if I want to discourage mice?

Sand, pine shavings, and aspen shavings are harder for mice to shred than straw or hay. Sand drains well and is straightforward to clean. Avoid cedar and walnut shavings, which are toxic to chickens. Change bedding frequently—at least weekly in warm months and twice weekly in winter.

Can I use poison inside the coop if I am careful?

No. Chickens are curious and will peck at poison pellets or eat dead mice that have consumed poison. Snap traps and electronic traps are faster and safer. If you must use poison, place it only in locked bait stations outside the coop, at least 10 feet away.

How long does it take to get rid of mice once I start sealing gaps?

You should see fewer mice within two to three weeks once you have sealed entry points and removed food sources. However, mice already inside may take longer to trap, and new mice may try to enter from nearby areas. Consistent effort over one to two months usually solves the problem.