Opening your camper in spring to find chewed cushions, droppings in the silverware drawer, and a nest behind the furnace panel is a rough start to the season. If you are searching "how to keep mice out of camper" or "how to keep mice out of RV" right now, you are doing it at the right time: before the rig sits parked and quiet for months.
This guide covers why stored campers and RVs attract mice, and a step-by-step plan for winter storage that works for travel trailers, fifth wheels, pop-ups, and motorhomes.
The Short Answer
Take out every bit of food and nesting material, seal the gaps where lines pass through the floor and walls, park away from cover, and check the rig regularly through winter. Scent repellents and traps can add layers, but a clean, sealed, regularly checked camper is what makes the real difference.
Why Mice Target Stored Campers and RVs
The National Pest Management Association (NPMA) says deer mice seek shelter in homes, garages, sheds, and rarely used vehicles during winter, and it recommends regularly inspecting rarely used cars and RVs. The NPMA also notes that vehicles left unused for long periods, or parked in rural areas, are at higher risk. A stored camper fits both descriptions.
The CDC confirms that rodents may build nests in cars, trucks, campers, and other vehicles. A camper offers cushions, insulation, and paper goods for nesting, plus cabinets full of quiet hiding spots. The University of California Integrated Pest Management Program (UC IPM) adds that house mice gnaw on electrical wires, which is how a camper infestation turns into a repair bill.
How to Keep Mice Out of Camper and RV Storage: Step by Step
Step 1: Remove Every Bit of Food
Empty the pantry, fridge, and every cabinet, including sealed packages, spices, and pet food. Wipe up crumbs and vacuum the floors, cushions, and under the seats before you store the rig. The NPMA points out that paper and food wrappers left in a vehicle can become nesting material.
Step 2: Take Out the Nesting Material
Paper towels, napkins, tissues, and cardboard boxes are easy nest material. Take them home, or store bedding and linens in sealed plastic bins. The NPMA recommends resealable plastic containers over cardboard for storage.
Step 3: Deal With Moisture
The NPMA lists leaks and damp items inside a vehicle as something that draws rodents in. Fix any roof or plumbing leaks before storage and take out damp towels and mats.
Step 4: Seal the Gaps
According to the CDC, mice can fit through a hole the width of a pencil, about 1/4 inch. Get down with a flashlight and look underneath and inside cabinets where plumbing, electrical, and propane lines pass through the floor and walls. The CDC lists holes for electrical, plumbing, and gas lines among the top places to check on any building. The NPMA notes that rodents can get into vehicles through vents, steering columns, and pedal shafts.
The CDC recommends steel wool held in place with caulk or spray foam for small holes, and metal or hardware cloth for larger ones. UC IPM warns that rubber, vinyl, plastic screening, foam, and wood are gnawable and do not hold up on their own. Do not block vents your furnace, fridge, or water heater need for airflow, and check your owner's manual or dealer before sealing anything that is part of the underbelly or appliance venting. Close every window and roof vent. The NPMA warns that a cracked window or open sunroof is an easy way in.
Step 5: Choose the Storage Spot Carefully
If you have a choice, park on pavement or gravel away from tall grass, brush, and woodpiles, which give mice cover right up to your tires. The CDC gives similar advice for homes: trim brush, weeds, and grass, and keep woodpiles away from the house.
Step 6: Protect the Engine on a Motorhome
If your RV has an engine, treat it like a parked car. Our guide on how to keep mice out of your car engine covers where to look and what to avoid under the hood.
Step 7: Check In Regularly
Checking the rig every few weeks lets you catch problems early. Look for droppings in drawers and under the sink, chewed packaging, and nesting material in corners. If you use traps, the CDC recommends snap traps over glue traps and live traps, and traps only make sense if you can check them often.
What About Dryer Sheets, Mothballs, and Ultrasonic Devices?
Mothballs are a registered pesticide, and the label controls how they can be used. EPA notes that registered mothball labels specify the use site as "air-tight containers and storage closets," and that using a pesticide in a manner inconsistent with its labeling is generally unlawful. Scattering them through a camper is not what those labels describe.
UC IPM says ultrasonic sound has very limited use in rodent control because it is directional, does not penetrate behind objects, and loses intensity with distance. We could not find an authoritative source testing dryer sheets for mice, so we cannot recommend them.
Opening the Camper in Spring
If you find droppings or nests, follow the CDC vehicle cleanup steps. Open the doors and let the interior air out for 20 minutes. On a motorhome, inspect the air intakes and filters before starting the engine. Wear plastic gloves, do not vacuum droppings or nests, soak them with a disinfectant for 5 minutes or per the label, and pick them up with paper towels. If you find chewed wiring, have the RV inspected before you travel.
Cheat Sheet
- Remove all food, including sealed packages and pet food.
- Take out paper goods and cardboard. Store linens in sealed plastic bins.
- Seal gaps of 1/4 inch or more where lines pass through the floor and walls.
- Do not block appliance vents. Check your manual before sealing.
- Close every window and roof vent.
- Park away from tall grass, brush, and woodpiles.
- Check the rig every few weeks through winter.
- Never vacuum droppings. Air the camper out and use disinfectant first.
Where BioGuard Fits
We sell BioGuard Natural Rodent Repellent, a pack of 12 scent balls infused with peppermint and cinnamon essential oils. In a stored camper or RV, it fits in storage bays, under sinks near sealed pipe openings, in the engine compartment of a motorhome, and in the storage area around the rig. It is a repellent, not a removal product. Replace it every 4 to 6 weeks, which lines up well with your regular check-ins, keep it away from children, pets, and food, and expect results to vary. For a realistic look at scent products, read do mouse repellent pouches work.
Frequently Asked Questions
How do mice get into a camper?
Usually through small gaps where plumbing, electrical, and propane lines pass through the floor or walls, through vents, and through windows or roof vents left open. A gap about 1/4 inch wide is enough, according to the CDC.
How do I keep mice out of camper in winter storage if I cannot visit often?
Focus on what lasts without you: remove all food and paper, seal gaps, close every opening, and park away from cover. Then visit as often as you realistically can, and replace any repellent on schedule.
Is it different for a motorhome than a travel trailer?
The living area is the same. A motorhome also has an engine compartment and air intake to check, so add the car engine steps.
Does peppermint oil keep mice out of an RV?
It can make spaces less inviting, but scent fades and no smell works alone. See our guide on whether peppermint oil keeps mice away.
Sources
- CDC, How to Seal Up to Prevent Rodents
- CDC, How to Trap Up to Control Rodents
- CDC, How to Clean Up After Rodents (vehicles, including campers)
- UC IPM, Pest Notes: House Mouse
- NPMA, Deer Mice
- NPMA, Vermin Threaten Vehicles This Winter
- NPMA, Pests in the Garage (plastic containers instead of cardboard)
- U.S. EPA, Pesticide Labeling Questions and Answers (mothball use sites)