Dear Dave,
What do you use to keep mice out of a camper, especially while storing it outside in the winter? —Kenneth, 2021 Keystone
Dear Kenneth,
There are two parts to the answer of this question: addressing entry points that mice can get in, and products that will keep them away. This has been an age-old debate with more answers and attempted solutions than just about anything else—other than maybe water leaks!
I live in Northern Iowa and we have a huge issue with mice during the winter as it gets brutally cold and they need to find sheltered protection. One year when I was working in Owner Relations at Winnebago an owner called and asked the same question. I recommended d-CON underneath, and he informed me that the mice just pick up the bait and fling it all over the coach and even bring it inside! He was storing the unit inside a large building that also had several thousand bushels of corn, so it was basically a mouse resort!
Both my grandparents lived on a farm and had issues with mice as long as I can remember. They used moth balls placed all over the house and had some success. However, the entire house smelled like moth balls all year, except for my Grandpa Judd’s house, that had a sensory battle with moth balls and King Edward cigars! He claimed the cigar smoke is what kept the mice out. My parents used moth balls in their Class A every year and never had mice. I guess they enjoyed the smell, minus the “King”! I personally did not like the smell, but it did dissipate after about a month of use. That was especially true if you happened to be in a campground with a good campfire smoke penetrating the rig—which I enjoy rather than the “King”!
Some RVers swear by dryer sheets placed throughout the rig, which smell better. But I personally worked on a rig a few years ago that had the sheets everywhere and the drawers and cabinets had evidence of droppings and chewing of toilet paper and other items. However, you will find many that swear the dryer sheets do work and I believe that it has more to do with the location, the rig, and how accessible it is for mice to get inside.
Part 1: Eliminate entry points
A mouse can crawl through a hole the size of a pencil. So you need to crawl underneath your rig and seal every opening you can find with foam sealer. You will see 1/2” drain lines coming down through a 1” hole that has a gap and maybe some sealant, but there is still a gap. Check out the video I did on inspecting the undercarriage and sealing on RV Lifestyle and Repair here.
Part 2: Deterrents
Whether you choose to use moth balls, dryer sheets, or d-CON, it is all a trial-and-error approach. One thing that has been proven is that mice do not like scents such as cinnamon, peppermint, and others. However, the challenge has been those liquid products dissipate or fade after a few days or weeks and then do not work.
One product that I have found is Mouse Free and it is a combination of a peppermint and cinnamon extract that is guaranteed for 1 year! I talked with a local “bug” applicator that indicated the secret is to combine the deterrent with a base product that will have a longer staying time such as when they use a “Teflon”-type product that lasts. Not sure what the Mouse Free product uses; however, it is more expensive and has to be applied with a paint sprayer method.
Another product that has seen some activity in the forums is Grandpa Gus’s bags that also feature a mint product and claim to last for 3 months but have no guarantee. I have not used the product; however, the reviews are good. But the challenge is that it takes several months to find out if they work. You can find it on Amazon here.
The old-school baits and traps are not deterrents and typically are not very effective, in my opinion. It is best to “rodent proof” your rig first and find a product that they do not like.
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We’ve tried dryer sheets. The mice used them for a nest. They ate the Irish Spring soap. We’ve had some luck with Grandpa Gus and we’re currently supplementing it with a peppermint based rodent repellent. We’ve been in our current location for about 6 weeks now, hosting at a state park. We’re backed up to a wooded area. So far so good….
In Texas, I park my rig in an area were we have rattle snakes, Road runners, fox and coyotes. A very hard place for mice to live, but having D-con green mouse and rat baits inside of plastic tubes with a screw on each end to keep the baits inside, and placed under the RV works great. Now ants are pests too, so ant baits are worth having inside the rig.
Kenneth,
I have a 5th wheel that has been stored outside in various yards since 1993. If yours is stored in storage facility summer or winter I have found thru experience to never park it on the perimeter. Ask for something in the middle. Generally mice will find the first comfy spot and shack up there. This has worked for me for years. I don’t even bother with dryer sheets, moth balls, etc, anymore and I never have a problem. My living circumstances prohibit me from parking in the driveway but I am told that a well maintained lawn cut short in the fall and leaves raked aids in keeping mice at bay. Combine Dave’s suggestions with the above and hopefully you will be mice free soon!!!
Good Luck,
Dave Johnston
I have the opposite problem, keeping mice out of my house since I’m full time on the road for work. I’ve had good success with a combination of the Grandpa Gus repellent and Fresh Cab. The Grandpa Gus packs (or spray) are extremely heavy cinnamon while the Fresh Cab packs are Balsam Fir Oil, which I find to actually be a pleasant smell somewhat like cedar. That combination has worked better than anything else I’ve tried over the last several years, though I do still put down traditional repellent sprays and granules around the outside of the house a few times a year for an additional layer. More than anything, the combination of different repellents seems to be key. None of them worked on their own but combining them has made a huge difference
Excellent tip! Thanks, Dan. Have a great day. 😀 –Diane at RVtravel.com
I have LED lights under the rig, peppemint oil soaked cotton balls in spice jars in the bays, and sprinkle used cat litter under and around the motorhome about once a month. So far, no mice or pack rats.
After years of fighting mice and loosing I decided to find out where they were coming in. Dead of night I lit up rv and the first thing I found was the slideout was carried by a square steel tube and the mice where getting into basement through the open end of the tube.
Closed that off and never had mice again. BUT, buy yourself some insurance, place a dozen snap trap around the rv. Can’t be too careful
I carry a BUNCH of mouse traps of varying sizes. If we’re camped someplace where we know there are mice (or any other vermin) I lay out a bunch of traps and poison. It’s war and I intend to win.
It is true that there is no deterrent that works in all situations. However, using d-con is one of the worst things to use.
We had a problem with my wife’s car in the garage. The mice were trying to build a nest on top of the engine. I put d-con in the garage and thought it was working until I looked under the hood and found the poison sitting on the engine along with the food they scavenged.
The poison also makes the mice look for a source of water and then die in the inconspicuous, hidden areas.
I found some Liquid Fence animal repellent. That along with snap traps solved the problem.
As far as sealing all the entry points, I stuffed the holes with stainless steel scrubbing pads, then some expanding foam.
This is a good point. Stuff steel wool in openings and then foam. Mice can and will chew through foam, but the steel wool will stop the chew through. The steel wool makes the foam stronger but if a mouse chews on the foam / steel wool, they get poked in the mouth by the steel wool and will look for another entrance.
For storage, old school mousetraps glued to paper plates of chunks of cardboard. Soften up tootsie roll or equivalent and mold over the trigger.
we have had good luck with product called Fresh Cab
In bright sun, I turned off all the lights inside the RV and drew all the shades, then stuck my head into every nook and cranny – including removing screwed on access panels. I looked for any glimmer of light and applied expanding foam. Then I reversed and at night, turned on every light and crawled the exterior of the trailer, repeating the foam process. Also, don’t store grains, pasta etc in the stored RV unless in tightly sealed, vermin proof containers.
We have had no rodent entry in six years of ownership; further, we find little or more often no signs of insect intrusion.
Look up Mousetrapmonday. Shawn Woods does real testing on all this stuff on his You Tube channel. As RVers find, not much works, at least not all the time, on persistent rodents.
One thing I do on a new motorhome is turn on every light in all the bays at night and climb underneath looking for any light. First time I did this was 1999 on my new Fleetwood Bounder. Looked like a Christmas Tree underneath with so many lights! All kinds of gaps and holes drilled too large.
I live in the country. I also keep numerous snap traps and a bucket trap with some antifreeze in the bottom in my MH shed. This really helps to minimize the population in the shed. I also keep two snap traps in the MH storage bays just in case.
To the person in the first situation parked in a building with a corn crib, cats!
Look up Shawn Woods on YouTube. He has tested almost every deterrent imaginable and also done extensive testing on mouse traps. Most all deterrents don’t work with an active infestation (trust me I tried in our old hunting trailer). However, he has found some very effective traps – and one that really shines is the Flip N Slide by Rinne Trap. Look up his YouTube channel and find years of testing.
Barn Cats earn their keep.
We’ve been using Fresh Cab and so far, we haven’t had a mouse problem. However, we also have blocked every space we think mice could get through.
Tried all the products mentioned.
None worked.
We were in a state park in N Arizona and got attacked by pack rats.
Lights under the rig helped
Finding entry points and filling the areas with steel wool worked better.
The combination worked better then anything.