A tractor or combine parked in a shed for the winter is exactly what a mouse is looking for: shelter, quiet, nesting material in the seats and insulation, and often some leftover grain or chaff. The damage usually isn’t found until spring, when a machine won’t start or a cab smells like a nest. This checklist covers how to prepare equipment before storage, where a deterrent fits in, and what to check before the first startup.
Why stored machinery attracts mice
- Shelter: engine compartments, cabs, air intakes and toolboxes are dark, enclosed spaces.
- Nesting material: seat foam, cab headliners and insulation are easy to shred.
- Food: grain, chaff and crop residue left in a combine, plus snacks and seed left in a cab.
- Easy entry: mice can fit through a hole the width of a pencil, about 1/4 inch, according to the CDC.
Before you park it: a storage checklist
- Clean out the cab. Remove food, wrappers, seed bags and anything that smells like food.
- Clean the combine. Clear out leftover grain and chaff, which is both food and nesting material.
- Pick the cleanest building you have, and keep clutter and debris away from where the machine sits.
- Seal the building. The CDC recommends filling small holes with steel wool held in place with caulk or spray foam, and covering larger gaps with hardware cloth, metal sheeting or cement. It specifically says to seal outbuildings and garages too.
- Store grain and feed in tight containers. Thick plastic or metal with tight lids, per the CDC.
- Open things up where practical. Moen’s directions for stored vehicles note that mice favor dark, covered spaces and recommend leaving hoods open when storing indoors.
Where a deterrent fits
Sealing and cleaning reduce the reasons mice move in. A scent deterrent adds a reason to stay away. Moen’s Mouse-Mix Farm Pack is made for this job: the manufacturer describes it as meant for the winter storage of tractors, combines and other farm implements, to help keep mice and rats from chewing on expensive wiring and upholstery.
How to apply it to a machine
- Divide the product into the included application bags and vent them.
- Moen’s vehicle directions call for placing bags on and around the engine and its wiring, and inside the cab. Apply the same approach to the tractor or combine.
- Set bags on a piece of cardboard rather than directly on plastic or upholstery. The label warns against placing them on finished wood, furniture or plastic.
- Put more bags along the walls of the building around the machine.
- Take the bags out of the engine compartment before you start the machine.
The Farm Pack is rated for up to 6 months of storage protection, which covers a typical winter. If you’re storing several machines or using more than one building, the 2-pack may be the better buy.
Spring startup check
- Look for droppings and gnaw marks, the two most common signs of rodents according to the CDC.
- Check the air filter and intake, the cab and the engine compartment for nests.
- Inspect wiring and hoses for chewing before you start the engine.
- Remove any deterrent bags from the engine area.
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
No deterrent guarantees a mouse-free machine. Mouse-Mix doesn’t kill mice; it’s meant to make an area unappealing to them, and results depend on the building, how long the machine sits and how the product is applied. If you’re dealing with a heavy infestation, the CDC suggests contacting a pest control specialist.