Our 5er has most of the penetrations to the exterior filled with foam from the manufacturer. The others that were not done became entryways for those rodents over the winter and I had to empty the trailer and decontaminate (wife's 'directions'). There were several areas in the front compartment that were not sealed and the belly covering needed several more self drilling screws to tighten it to the cross member. Under the kitchen and bathroom sink I found the 1-1/4" drains were put through a 3" hole, now filled with foam. The HW heater is under the counter and had a direct path to the belly - now sealed with a piece of luan plywood and foam. I haven't used steel wool on this RV but found some stainless steel kitchen scrubbers at a dollar store for the last one - and they work well and wont rust.

This is one of the 'joys' of owning an RV

 

I have sealed all I can and the dang things still get in. The best solution that I have found is to relocate every black snake I find out to the camper shed. As long as I can keep a snake in there I do not have mice.

 

Just a quick question - is your electric cable through a hatch or do you plug it in a surface receptacle? On the now gone 5er we had mice crawling up that cable (as well as through the pin box penetration to the frame if I let the truck hook up cable dangle when parked - also had a birds nest in the pin box once but that's another unrelated item to this thread)

Black snakes as you said, cats, ferrets, hawks, owls also will help eliminate mice but you might have a problem keeping their attention span on the trailer

 

My electric comes through a hatch. It does not seem to matter whether I have it plugged up or not, the mice will still find a way in.

 

How 'bout something like this?

 

Fresh Cab® Rodent Repellent | earthkind


This stuff has worked in my Cadillac for Winter Storage. I have no association with the company, but Fresh Cab has worked for me.


A note: Every three months replace the bags as if you let them stay too long they will be eaten by the mice.


I use these AND the dryer sheets in the engine compartment, trunk and inside the cab and so far no mice damage and the car is stored on a farm house type of flat.


Just my .02

 

We had mice and ants for years and tried many home solutions. The one that works for us is pure peppermint oil. We leave a bottom covered amount in paper coffee cups (not plastic or styrofoam, they melt) throughout the trailer. Smells good and permeates the basement and bottom of our 5th wheel. I can smell it underneath the trailer. Haven't seen any trace of mice or ants using the oil.

 

We have a 2004 Komfort 25', they claimed it had a "sealed bottom", it's been "semi-permanently" parked on our property in SW colorado for 8 years. Found mice getting inside 3 ways:

While camping:

1) The electric power cord had a small gap around which they squeezed through. I use steel wool now with duct-tape over the top to minimize rust from rain (after all, camping causes rain, even in the normally dry-season)

While away:

1) The access panel to the rear of the refrigerator allowed mice into that area, they then ran up through the insulation into the space between the inner/outer ceiling and then down behind the shower and got out under the kitchen sink (the water lines go through an access hole between the kitchen/bathroom). I bought a roll of fine mesh aluminum screen and installed sections across the inside across the large openings in the panel.

2) Where the power cables to/from the batteries penetrated the underside had gaps which allowed mice in there. I installed some low expanding foam to seal the gaps and then put shipping tape over it.

Just had our first visit with no evidence of mice. The wife was VERY pleased.

 

Don't quote me on this but I believe peppermint oil is what is in the stuff I was talking about...

 

My wife ordered some peppermint oil along with some natural stuff that kinda smells like wintergreen as one of our pups, 8 month old Molly, will chew on anything that isn't nailed down. Since my major clean out and hole chase down and filling we haven't had a mouse back in the 5er even though it's parked in a former orchard at our seasonal site. Time will tell though

 

I got some bags of "eco-friendly" smelly stuff and threw them every where inside. No mice since then!