Saturday, January 29, 2022


What works when your housey is lousy with mousies?

By Russ and Tiña De Maris

It all started with a letter from Don Callahan, a long-time reader. Here’s Don’s missive: “I read in a number of places that Irish Spring bar soap was a deterrent to rodents in RVs. I put a number of bars around in my motorhome last fall when I stored it. Today when I was going to install the chassis battery I found that the two bars of Irish Spring I had placed in the battery box area had been partially eaten and there were a lot of mouse/vole droppings around it. Amazing.”

Don is an Alaska resident. Are cold-weather mice hardy? Or, after several long months of winter, maybe they just need a good bath, and a few nibbles of Irish Spring and a breaking of the ice on a nearby puddle are all they need to get spiffed up for spring. In any event, it brings up the perennial question: Just what can you use to successfully keep rodents out of your RV?

Stinky stuff

Moth balls: Ygtcefuoram 095 on wikimedia commons

Certainly Irish Spring falls under the old odiferous offering category. You can add to it moth balls and cotton balls dipped in peppermint oil. The theory goes that since mice and their kinfolks have sensitive noses, putting out something that is proboscis potent should send them fleeing into the next county. Good in theory, but usually not too effective in practice. Why is that?

First, a little mouse psychology. Put yourself in a mouse’s place. If all your enemies were bigger than you, had sharp teeth, and were terrifying, just how quickly would you be willing to move out of a safe shelter where the big guys couldn’t get at you? Would you be willing to put up with a little smelly stuff to have a safe place? Think rats in sewers. Tell me, just how bad does a sewer smell? Yes, it’s possible that if you could whip up a stinky batch of Irish Spring, peppermint oil and moth balls you might be able to run off the rodents – but think of what the stuff would do to you.

Perhaps peppermint-scented cotton balls will deflect Herman the Mouse, but unless you put them just about everywhere in your RV it’s quite likely they’ll just learn to avoid the immediate smelly area. The same seems to be so for the next techno-mouse repelling idea.

Ultrasonic shooing systems
Described by one marketer as “unique devices that are designed to drive away ants, spiders, mice, rats and cockroaches only using ultrasonic sound waves,” these not-so-cheap electronic devices are sworn enemies of mice and bugs. The marketing trumpet goes on, “That means no unpleasant odors or dangerous chemicals to inhale and no messy, toxic sprays that may put your pet in danger.” Do you buy that?

If you do, remember, you probably also left a bunch of cotton balls lying around in the bottom of the dinette cabinet, soaked in peppermint oil. Now envision hordes of mice making a beeline for your dinette cabinet, grabbing ahold of those same cotton balls, ripping off chunks, wadding them up, and stuffing them in their little mousy ears. They smile as they go about their daily routines in your RV, now oblivious to your “unique devices.”

Once again, strength and area are problems for these dream machines. In order to be safe for pets and users, the noise strength of these clever devices has to be kept down to a dull roar. Even if they were like the proverbial “fingernails on the chalkboard” to rodents, the intended target audience would simply move out of the effective range of the device.

Mouse poisons

Many of these potent potions really do spell death for mice. But they also come with their own set of drawbacks. Some of them are consumed by mice, who don’t die instantly. Some cause the critter to develop the effective equivalent of a hemorrhagic disease – their blood vessels start leaking out their vital fluids in a torrent. No doubt the mouse feels terrible, so instead of dropping dead on your kitchen floor, he drags himself off to a quiet, dark and sheltered place to die. Come time to travel, you only know the stuff was effective when you open the door and smell the decomp. Now try and find that quiet, dark and sheltered place to retrieve that body!

Some years ago we had a bad infestation of mice in a food storage area. We put out little boxes of green pellets, guaranteed to make mice beg for their last meal. The mice found the stuff – and carried it off to the other end of the rig where they carefully squirreled it away in a sofa. Enter three-year-old grandson – who made the remarkable find in the couch. Picture terrified grandparents dumping ipecac syrup in the squalling kid’s mouth in an effort to get him to upchuck the mouse poison. He survived, and now has a rug-crawler of his own, but the nightmare really never goes away.

Forget the stuff that doesn’t work. Throw out the ideas of poison baits that can create bigger problems than they cure. Here’s what REALLY works:

Cut off the food supply

Your rig is a great haven for mice, but only if they have the necessities of life. When you put your rig in storage, make sure you don’t leave stuff behind that rodents will find life-sustaining. You like to snack while RVing? So do mice! Don’t leave behind stuff like crackers and chips. A box of Cheerios is great cheer for a hungry mouse. And stuff you might not immediately think of includes powdered coffee creamer, sugar, flour and baking ingredients. Uncooked pasta, nuts, dried fruit and trail mix, candy and granola bars are easy mouse targets.

And don’t think that your precious commodities that you’ve carefully concealed in plastic containers with sealed-tight lids will keep away a determined rodent. With plenty of time on their little paws, busy teeth can make for holes big enough to access tasty snacks.

Roll up the draw bridge

Not quite as good as steel wool

Secure your rolling castle by keeping the rodents outside your walls. Mice can squeeze through tiny cracks and holes and come in like an occupying force. It requires effort, but you need to make a thorough inspection of your rig. Crawl underneath and look for any cracks or holes. Inspect where utilities enter or leave – electrical port, water hatch, gray and black water pipes passing through the floor. Expanding foam, cautiously used on some things, will do a pretty good entry prevention trick. Steel wool is also another great hole fixer – mice can’t chew through it to gain access.

Keep your rig clean, remove any attractive food supplies when the rig isn’t in use, and always ensure that the welcome mat is never extended by keeping all outside access to your rig closed off. And what if an enterprising rodent still makes it in? We found spring traps, baited with peanut butter, were simply irresistible to a fat little mouse that had the audacity to eat raisins right off our galley counter while we slept.



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Terrence Courtney
3 months ago

Living in the AZ desert, rats love the area with falling cactus flowers for them to store for the winter. I have used most of the methods commented on the Post to rid the pest and yes, found peanut butter and trap the most effective eliminator. One thing to remember is the pest have GREAT SMELLERS. If you are laying out a means of removing them, make sure you clean-up their previous visit otherwise they will smell it and say to themselves ” Ah…Home Sweet Home”.

John Hicks
3 months ago

Bronze wool will not rust.

Seann Fox
3 months ago

Mice are creatures of the darkness they don’t like light. Knowing this I bought some solar flood lights from Amazon and put them under the RV making sure it was well lit. I haven’t had a problem with mice since.

Stephen Malochleb
3 months ago

I’ve tried all the known repellants. So the best I’m come up with. I put up a shelter logic a couple of years ago, There was a ferrel cat in the neighbor hood. So I gave him a bed in the shelter, give him food and water, and no mice. As long as he does his part, I’ll do mine. A good partnership.:):):)

Terry Monos
3 months ago

We use the electronic units,4 of them, plus peppermint oil on cotton balls in plastic cups in the living quarters. Use Moth Balls in plastic cups in basement storage. There are different peppermint oil,found that Mentha Piperita oil last longer and smells stronger. Tried Irish Spring Soap and bags of Cab Fresh but didn’t work on our mice.

Lin Watts
1 year ago

Well Okie rodents must be some of the sneakiest critters on the planet. We have to keep all car hoods raised, or the pack rats will move in quickly sometimes overnite, especially if its cold and rainy. Deer mice and packrats have eaten all the insulation off the firewall AFTER spraying under the hood with Mint oil, and chewed the speedometer cable from another vehicle. I bought a rodent repeller that hooks up to the car battery and emits a high pitched sound for $40 and they ate the wires off of it. I did get to meet a lot of nice people in parking lots that kept telling me my car was making a funny noise lol. We saturated cotton balls with mint oil and hung them throughout the engine compartment where they worked quite well for a while but then we found rodents nesting in the cab. We haven’t tried the Red pepper sprinkled over the engine yet as keeping the hoods up is working. I cannot recommend steel wool or moth balls. When our renter moved out she left behind dozens of mice and we tried blocking the holes around pipes with steel wool and spreading mothballs under the sink cabinets. They came back after pushing through the steel wool and CHEWED the mothballs up! Alas we resorted to traditional mouse traps placed around the edges of the room, replaced after each catch and foamed insulation in every crevice we could find.
Last year we purchased a 19 ft bunkhouse and knew we wanted to preserve it so hubby made sheet metal covers with the bottom enclosed to cover the tires – rodents couldn’t climb them. The tie downs and hitch are also covered with this smooth sheet metal flashing. So far its working – fingers crossed.

1 year ago

Moth balls. Only once did we have a problem with rats in our RV. She nested in the engine bay. I put moth balls in old panty hose and we placed them all over the engine. She and the babies were gone the next day. Since then, we keep moth balls under the hood. You just have to remember to remove them before a trip or starting the engine. Also, replace them as needed.

We have never had a problem with critters getting to the inside of our RV because as soon as we brought the RV home, we went over it and sealed ANY opening we could find. We live in an older area where the houses were built off grade and there is a nearby bayou and bay. Rats are the neighborhood mascots. Everybody around here knows to seal up tight against the critters. We had never had a problem with rats getting into our vehicle engines until the problem with the RV. Probably because it is not used as much as our other vehicles.

Mammals do not like the smell of menthol or moth balls. I use this to discourage my own dogs from “marking” around my husband’s motorcycle tires.

1 year ago

We had mice once and believe me, they don’t need your food! They ate plastic bags, bedding, clothes and towels – anything they could eat and also use for nests. Found dead babies as Mom probably couldn’t get enough nutrition. Steel wool in every hole or tiny space where you can see light works. Then foam over it. They will eat the foam maybe, but it slows them down and when they get to the steel wool they are further discouraged.

1 year ago

We have done battle with Pack Rats In Arizona and won! Or at least we hope. Used rope lights, battery operated sonic repellents, large plug in sonic rat repellents, rat traps, steel wool, foam sealer and rodent spray. We also started the generator and Diesel engine frequently. Upon inspection of the engine again in Colorado, only sign of them was a left over cholla. Doubt that was a happy snuggle up item in their now long gone nest.
Only Problem is that I don’t know what really shooed them away. Well, the rat traps for sure.

1 year ago

Peg, how do you get the coyotes to pee in a bucket for you😊?

1 year ago

We must have the most attractive rodent hotel in the the world! We have tried Irish Spring, Bounce sheets, peppermint oil, coyote urine (!), FreshCab, PestRepel (from the exterminator), rosemary branches, traps baited with peanut butter, traps baited with bacon, traps baited with cheese, sticky traps, large traps, small traps, electronic traps, snap taps, lights under the vehicle, electronic pest repeller, professional sanitation, all to no avail. After over $20,000 worth of repairs (including rewiring the entire coach and plugging all access holes we could find) we finally resorted to a pest control service, that yes, uses poison (gasp)….yet we still have the nightly visitors….so if someone, anyone, can come up with a solution we’d LOVE to hear about it.

1 year ago
Reply to  SDPeg

Traps are ultimately the only thing that works – unless the buggers are too smart and figure those out in advance.

3 months ago
Reply to  SDPeg

Install a cat! (Also check your tail and brake light cavities!)

Lisa Adcox
3 months ago
Reply to  SDPeg

I do not think we know every area they can get in at. We had what I call a hitchhiker after travel trailer was in for warranty work. So we put traps and deterrents out but still knew one or two was still around. So I put 4 of the electronic plug in inside tt. Two days and no mice. I also put Fresh cab in cabinets and such. So far so good two years later.

Lynn Loftis
1 year ago

We have a problem with squirrels. They get into the trailer and store acorns all over the place. We have tried sealing up holes and bait outside the trailer but if its parked at the house for any length of time they find a way back in.

Tommy Molnar
1 year ago
Reply to  Lynn Loftis

There is a squirrel trap out there called the Squirrelinator. This thing works wonders. I put it out and caught six of them in under an hour. Loaned it to my neighbor and in a couple of hours he too caught eight. A bit spendy, but if you have a squirrel problem it’s worth every penny!

Jerilyn Lessley
1 year ago

We used mouse traps. In fact, we caught two in the same trap at the same time. My goal was ‘no’ mice. I crawled everywhere I could get to and filled every open space with steel wool. I even took vent covers off and checked there.
We haven’t had any for years (knock on wood). I still keep a trap near my sink.
One more thing, I try to park So no body part is near vegetation.

1 year ago

Parking is an issue. In our yard, parked over dirt, and in places with grass under or nearby we have had them. Parking over concrete out in the open has helped keep them out. I think they don’t want to be seen by predators in the open. Hope your luck holds out!

1 year ago

Please remember that poison not only kills mice but the creatures that eat them. The sticky traps when placed outside will trap other innocent creatures such as birds. I don’t care about the mouse, but I do care about raptors and birds. Food for thought.

1 year ago

Fresh Cab seems to work pretty good.

The main thing is, we don’t leave ANY food of any sort in the motor home when we are at home. We clean all the crumbs from the areas where we keep food.
I think a mouse or two came up the shore power cord where it goes through the plastic hatch in the bottom of the compartment. Filled the small gap with steel wool, haven’t seen any evidence of mice since.
I look in all the compartments every couple weeks, and check around inside while dumping and refilling the Dri-Z-Airs.

1 year ago

Traps as well as I try to block access. Where easy to do so. I cut a 5 gal pail down to about 12 to 15 inches and put jacks or legs in the pail. For added protection put an inch of fluid (oil) keeps the ants out too.

J anne
1 year ago
Reply to  Wayne

Please explain
I do not understa.d this.

Tommy Molnar
1 year ago
Reply to  Wayne

I like this idea. Think I’ll give this a try.

1 year ago
Reply to  Wayne

Yes that will work but what about the tires

chris p hemstead
1 year ago

Peanut butter in a standard trap. Kills instantly. Leaves mouse where you can find him. No long drawn out death. Works for me.

Linda K
1 year ago

Not instantly. I caught a mouse in a standard trap several years ago and laid in the dark listening to the horrifying sounds of screams and violent thumping for several minutes. Ugh!

1 year ago

Better than steel wool for sealing cracks–it rusts and disintegrates–is copper mesh. More expensive, but worth the cost.

Michael Buchanan
1 year ago

I use a product called Max Catch Sticky Peanut Butter Scented Best Mouse & Insect Glue Boards available through Amazon. These boards are ultra sticky. You need to be careful in placing them. Getting a finger stuck on one is no easy task removing. I add a little real peanut butter just for effect and it works wonders.

Tom Smithbrother
1 year ago

A great article. thank you.