Pole barns and equipment sheds are hard to keep mice out of. They’re big, the doors are open half the day, there are gaps where the walls meet the ground, and they’re usually full of things mice like: stored feed and grain, bedding, insulation and quiet corners. You won’t make a pole barn airtight, but you can make it a lot less inviting. Here’s a practical order of operations.
1. Look for signs first
The CDC lists droppings and gnaw marks as the two main signs of rodents, and they usually show up before you see a mouse. Check:
- Along the base of walls and in corners
- Around stored feed, seed and grain
- Inside cabinets, toolboxes and tack trunks
- Around insulation, especially near the eaves
- In and around parked equipment
If you clean an area and droppings come back, mice are active there now.
2. Seal what you reasonably can
Mice can fit through a hole the width of a pencil, about 1/4 inch. According to the CDC: How to Seal Up to Prevent Rodents guidance:
- Fill small holes with steel wool, held in place with caulk or spray foam.
- Cover larger gaps with hardware cloth, lath screen, metal sheeting or cement.
- Check where utility lines enter: electrical, water and gas.
- Check doors and windows, especially ones without weather stripping.
- Look at the gap between the foundation and the ground.
In a pole barn, focus your effort on the enclosed parts: tack rooms, feed rooms, workshops and any insulated section. Those are easier to seal than the whole building, and they’re where mice do the most damage.
3. Take away food and shelter
- Store grain and animal feed in thick plastic or metal containers with tight lids, as the CDC recommends.
- Clean up spilled feed and grain promptly.
- Keep clutter, scrap piles and old bedding to a minimum, especially along walls.
- Store bags, tarps and seasonal gear off the floor where you can.
4. Add a deterrent where you store things
Moen’s Mouse-Mix Farm Pack is made for large buildings and outdoor storage, and its label lists barns, sheds, grain storage areas, tack rooms and stables. It’s a scent-based deterrent made with natural spices and oils, so there are no poisons or traps to manage.
- Divide the product into the included application bags and vent them.
- Place bags along the walls and in the corners of the areas where you store feed, tack and equipment, following the spacing in the included directions.
- In a big open pole barn, start with the enclosed rooms and the walls closest to what you’re protecting, rather than spreading the product thinly across the whole floor.
- Put more bags in and around any stored machinery. See Keeping mice out of tractors and combines in winter storage.
- For several buildings, the 2-pack gives you two buckets.
Keep bags off finished wood, furniture and plastic, which the label warns can be discolored or stained.
5. Clean up safely
Clean up droppings safely. The CDC says not to sweep or vacuum rodent droppings or nests, because that can put virus particles in the air. Wear rubber or plastic gloves, spray droppings with a disinfectant or a bleach solution (1½ cups of household bleach per gallon of water) until very wet, let it soak for 5 minutes, then wipe up with paper towels. Full instructions: CDC: How to Clean Up After Rodents.
Limitations
A deterrent won’t fix a building that’s open to the field on every side, and it doesn’t kill mice. Expect the best results when you combine sealing, food storage and a deterrent. For a heavy infestation, the CDC suggests contacting a pest control specialist.