How to Keep Mice Out of the Barn
It's that time of year again! When the weather turns chilly, mice start looking for a warm place to nest.
If you have horses, you know that a mouse infestation in the barn is not only a nuisance and a serious health and safety risk; it can also cost you hundreds (if not thousands) in contaminated feed and chewed tack, and increases the risk of a deadly barn fire.
To help keep your barn and horses safe, we‘ll look at the dangers mice in the barn can pose and tangible steps you can take to get mice out of your barn - and keep them out!
Why Does Keeping Mice Out of The Barn Matter?
Mice Cause Illness
While tiny mice may seem harmless, they can pose a serious threat to horses and humans. Mice can carry a variety of diseases, including Leptospirosis, lymphocytic choriomeningitis, plague, and typhus.
Deer mice also carry the hantavirus, a potentially fatal disease characterized by fatigue, aches, fever, and trouble breathing, and is caused by inhaling particulates from their urine and droppings.
Mice Can Cause Barn Fires
Barn fires are a serious problem in the United States, with an estimated average of 1,200 barn fires happening every year. These fires often result in the death of horses and other animals.
Many barn fires are caused by pests, like mice, chewing on electrical wires. Barns are typically dry, dusty environments, usually made of wood, and full of combustible items like hay and straw, so even a small spark can cause a fatal fire.
Additionally, barn wiring is often old, outdated, and/or not regularly inspected, meaning damage can accumulate over the years.
Mice Ruin Grain
While a mouse can survive on very little food, the average mouse will consume about 3 grams of grain per day. This may not seem like much, but it can add up quickly.
In chewing through feed bags, the remaining grain is subject to mold growth and contamination from mouse droppings.
To make matters worse, a barn with a mouse infestation may also have issues with other small rodents, depending on where you live. Other pests like rats, chipmunks, possums and shrews can cause a significant portion of your grain supply to disappear.
Mice Destroy Tack
Mice don’t just love pillaging your most recent feed shipment- they also love destroying your expensive tack, too. Mice will happily gnaw on most leather goods, especially bridles and strap goods that might be left on the ground.
Soft goods like saddle pads, pillow wraps, girth covers, and blankets are also at risk. Anything that’s soft and woven makes great bedding for baby mice, so expecting mother mice will pull the fibers apart to build nests.
Fortunately, you can do a few things to keep those pesky critters out. Here are some tips:
How to Keep Mice Out of the Barn
You’ve got a good understanding of why it’s so important to keep mice out of the barn. But it’s easier said than done! Here are our top tips and tricks to make your stable less appealing to rodents and keep mice out of your barn.
Seal Up Cracks or Openings
Mice can squeeze through very tiny spaces, so it's important to seal up any cracks or crevices. You’ll most likely find these around doors, windows, ventilation systems, drainage holes, or anywhere else the inside of your barn meets the outside.
It’s tempting to only patch holes from the inside, but remember most mice will sneak in through an external (outside) hole, so check the exterior of your barn for any holes or gaps that need to be filled.
Mice only need a space about the size of a nickel to get inside, so don't underestimate them!
How to Seal Cracks & Crevices in the Barn
Cracks and crevices around doors and windows can let in both mice and drafts, so here are a few simple ways to seal up these gaps and help keep your barn warm and rodent-free.
Weatherstrip tape
One option is to use weatherstripping tape, which comes in various materials, including felt and vinyl. It’s great for narrow gaps around doors, doggy doors, and windows.
To use, first clean the surface around the door or window, remove the backing from the tape, and press it into place.
Caulk
Another option is to use caulk, which can be applied with a caulking gun.
For best results, choose a caulk designed for use on windows and doors. If you’re caulking a gap in a stall or where a horse or other animal can get at it, make sure to use non-toxic caulk and check it for signs of wearing or chewing.
Steel Wool
If you have any openings that are too large to seal with caulk, try using steel wool.
Simply stuff steel wool into cracks or gaps. Pack it tightly enough so mice can’t crawl around it. It’s perfect for uneven gaps around pipes or ventilation equipment.
Expanding Foam
For filling the largest gaps, expanding foam is your best bet. This should not be used in areas where horses are left unattended (like in a stall) in case they chew on the hardened foam.
Following the manufacturer's instructions, just apply the foam to the middle of a crack or gap, and it will expand to seal the opening. Wear rubber gloves and have plenty of rags and paper towels ready if the foam expands more than you expect.
These materials will block mice from getting through while allowing air and light to pass through. Just make sure to check regularly to ensure that the mice have yet to find a way around them.
Keep Your Barn Clean and Organized
A clean barn is less inviting to mice than one that’s full of clutter.
An organized barn keeps equipment safely packed away, food stored in rodent-proof containers, and has minimal entry and hiding places for mice. A clean barn keeps mice-dropping contamination to a minimum and eliminates the fallen and leftover grain that attracts mice.
Here’s what you can do every day to make your barn as unwelcoming to mice as possible:
Sweep Up Regularly
Sweeping doesn’t just make barn aisles look good and cut down on dust - it also removes potentially disease-carrying mouse droppings, which helps keep humans and animals safer.
Regular sweeping also removes dropped grain and leftover food, which attracts mice and other pests. If you have barn pets, like cats or dogs, keep their food area especially clean.
Keep Food in Containers
Paper bag grain sacks are useless for preventing mice from getting into your grain (and don’t protect against moisture damage, either). Here are a few better options for storing grain-
-Old chest freezers - heavy and can be hard to find, but you won’t find a more secure container (and you can get broken freezers for free).
-Metal garbage cans - they’re loud, but pretty much rodent-proof. Bonus points for them being non-porous and easy to disinfect.
-Wooden boxes - an easy DIY project to store grain bags, but they usually need to be metal-lined to keep rodents out long-term. ‘
-Plastic containers - cheap, colorful and easy to find, plastic containers like garbage bins and lidded pails are a common choice for keeping mice and moisture out, but rodents can chew through them eventually, so check and replace them as needed.
Eliminate Nesting Options
Barns are warm, abundant in food and full of soft tack items like saddle pads and wraps that make great nests for expectant mother mice to raise their babies.
To make your tack room a less-than-ideal mouse nursery, don’t store nesting materials like hay and straw in the same barn as tack and horses (which is also a good fire-prevention measure).
Store wood shavings in the manufacturer’s bags and off the floor to prevent moisture and mouse contamination.
Keep Floors & Walls Clear
If you’ve ever watched a mouse operate in the daytime, you’ll notice they usually scurry along walls from hiding place to hiding place, instead of running around in the open.
If possible, avoid storing items on the ground along the wall (think tack trunks, blanket bins, and other large items). This reduces hiding places for mice.
How to Get Rid of Mice in the Barn
Use Mouse Traps or Repellents
If you already have mice in your barn, you'll need to take more aggressive measures to eliminate them.
Try setting mouse traps baited with cheese or peanut butter near areas where you've seen them before. If you have loose dogs on the property though, avoid food baits. If there are children or cats around, either put traps in places they can’t access, or try hiding the trap in a box with a mouse hole cut into it.
You can also use ultrasonic repellents, which emit high-frequency sounds that deter rodents without harming humans or animals.
How to Use Ultrasonic Mouse Repellents
Ultrasonic mouse repellents are a popular way to keep mice out of your barn. They’re non-lethal and safe around kids and other pets.
Ultrasonic repellents emit high-frequency sound waves that are undetectable to humans but very bothersome to mice. These sound waves will keep mice away from the area where the repellent is used.
Most ultrasonic repellents are safe to use around children and pets. However, reading the instructions carefully before using any pest control product is important.
Get a Barn Cat
We saved the cutest solution for last! Probably one of the first suggestions you’ll get if you ask barn owners what they do to keep mice at bay, there are several reasons why barn cats are a favorite tool for preventing mice in the barn:
1. Mice Control
Obviously. One of the primary reasons to get a barn cat is for mice and rat control. A barn cat will help to keep the mouse and rat population in check, preventing damage to your property and protecting your food supply.
2. Natural Pest Control
Another reason to get a barn cat is for natural pest control. In addition to mice and rats, barn cats will also help keep other pests, such as snakes and spiders out of your barn. This is beneficial as it helps reduce the need for chemical pesticides, which can harm the environment.

3. Companionship
In addition to being helpful around the barn, barn cats also make great companions. They are typically very affectionate and loving animals that enjoy spending time with people. If you spend a lot of time working in your barn or are looking for a “barn greeter” to amuse clients, having a barn cat around can help to make the experience more enjoyable.
4. Reduced Euthanasia Rates
Another benefit of getting a barn cat is that it can help to reduce euthanasia rates at animal shelters. Barn cats are often cats that have been abandoned, born feral or are otherwise not suitable for living indoors. By adopting a barn cat, you can provide it with a loving home and help reduce the number of cats needlessly euthanized each year.
Conclusion
Mice may be small, but they can cause big problems in your barn if they're not kept in check. By sealing up any openings, using mouse traps or repellents, and keeping your barn clean and organized, you can discourage these pests from taking up residence in your horse's home.