Thursday, September 22, 2022


One very easy fix to keep mice and other freeloaders out of your RV

As full-timers, we constantly work to keep mice, bugs, scorpions and other creepy crawly creatures from entering our house on wheels. One of the easiest openings for these critters to ingress is your wet bay around the sewage discharge pipe. While wet bay configurations differ, in most RVs there remains as much as a .75” to 1” inch opening around the diameter of your dump hose. This hole is an open invitation for critters to migrate to other areas of your RV. So how can you prevent them from hitchhiking?

This is our 2-inch square EDPM foam that is frequently sprayed with Home Defense insecticide to keep those critters from crawling up the hose and further into our RV.

No freeloaders, please!

After hearing many suggestions from twisting towels to steel wool around the pipe, what worked best for us was EPDM (ethylene propylene diene monomer) foam rubber. This closed-cell foam is typically used as a weather proofing sealant around doors or windows and in the automotive industry. It comes in many sizes and shapes. We chose to use square, non-self-adhesive, as it is easy to press-fit around the pipe and we can soak it with insect repellent. If we chose the foam with a self-adhesive strip, the insect repellent would eventually dissolve the self-stick adhesive.

Where can you obtain it?

You can get it at the usual big box stores: Homeless Depot or “Woe-is-Me” Lowe’s. Also, most reputable hardware stores carry it. We purchased approximately three feet of 2” EPDM foam with no adhesive. It’s also available on Amazon.

The foam is press-fit around the sewer hose and soaked with insecticide. This picture was taken prior to us leaving Puerto Penasco, Sonora, Mexico, back to the Lower 48.

Force fit works perfectly

We simply cut it to the approximate length and manually stuff it around the pipe at every setup. And from time-to-time, we refresh it with insect repellent to keep freeloaders from the snacks in our pantry. When we pick up to travel once again, we merely set it to the side in the wet bay until we stop at the next destination. (You can read about our Gulliver’s Travel nightmare against the armies of ants in Southern California here.)

The only place the ants didn’t penetrate was around the sewer hose. Gee, I wonder why? The “sand” particles in our wet bay are from last month’s stay directly on the beach in Puerto Penasco, Sonora, Mexico. It was a wonderful trip and we took no freeloaders back to the states.



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6 months ago

As soon as I get parked and set up I get my garden spray can out and spray everything that touches the ground, tires, stabilizers and tongue jack and I don’t connect to the the sewer until I need to dump. Once you get critters in your trailer or RV they are very difficult to get rid of. Once was enough for me.

Tommy Molnar
11 months ago

Amdro for ants can’t be beat. If we camp somewhere where we spot ants right away, we quickly give them some Amdro, which they seem to love. They haul it back to the ‘den’ and within a short time they’re all gone.

11 months ago
Reply to  Tommy Molnar

I’m with ya on this. Good stuff

11 months ago

I LOVE this tip! Thank you!

11 months ago

I found the best way to keep the critters from climbing up my Stinky Slinky, is to only hook it up and use it when needed, then put it back up. Not leaving it hooked up all the time left the critters looking for neighbors with a ramp to their house on wheels! Works every time!

Su rank
11 months ago

We had an army of tiny ants throughout our camper when we were at softball games. I was in panic mode. Found out there were ant hills at recptical area and sewer and water hook up. My husband years ago was an rv technician and he went to work rubbing Vaseline around hoses and sewer and elec cord leading to camper. Solved problems but the inside we bought traps and put everywhere, plus bombed rv as we would be gone all day. A nightmare

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