Mice - Any advice on where to look for points of entry?

IMO, you really need to seal it - the deterrents work like this: I'm a mouse. I want to build a nest, and I'm going to build it at the best possible place I can find (able to be warm, safe from predators, etc...). If this place happens to be smelly (peppermint) or filled with irritating noises (ultrasonic repellers), that makes it "less good", but if it's still the best place I can find, I'm still going to build my nest there.

I use the smelly stuff and ultrasonic devices in my van, and they help a lot but don't work 100%. I still end up having to replace the cabin air filter every spring (they really like nesting in that). Sealing up my trailer completely has worked 100% for four winters now.

Personally, I'd remove the underbelly panels and seal everything up. My trailer doesn't have those panels, which made it somewhat easier for me. You can also get MOST of the holes from inside the trailer. There were only a couple (gas line under the furnace, for instance) that I couldn't get from inside the trailer.

soak cotton balls in peppermint oil (real peppermint oil, not the phony stuff) and put them into plastic pill bottles with holes drilled in the bottles. Mice can't stand the smell of it.

I seemed to have a mouse issue every winter so I bought a roll of black eternabond and sealed the edge of my coroplast belly to the frame and any opening for the pipes. I'm out $75.00 but knock on wood, no mice since then.

So here's the quandary - the enclosed never belly meansi can't see any of the seals where the wires, pipes and other things enter the trailer. There are a number of places where something could enter the enclosed underbelly (slide tracks, air vents, etc...), but these are necessary openings and we have no idea what the holes might be that actually allow the mice into the trailer box itself.

Short of taking down the entire underbelly, is there any way to try to tackle this?

Check for any opening 1/8 inch or more and use expansion foam . What I do is take zero steel wool fill the hole then foam it then when they try to chew into the foam they cut up their mouth.

I sealed mine up using a couple cans of "Great Stuff" and a lot of work. I found openings for gas lines, electrical, and plumbing. Most of these were inside false walls in cabinets or cabinets that were screwed shut and not meant to be used. The drain line for the tub also went down through the floor under the tub itself - that one was the most difficult to get to and seal. Also, if the metal or plastic pieces inside your wheel wells don't mate perfectly with the walls/floor, seal those openings too. Basically, it's a rectangular box - open up anything that is blocking you from seeing the exterior wall and seal up all openings no matter how small. (Mice can get through a hole a quarter inch in diameter.)

When winterizing I also cover the vents for the refrigerator and the furnace with aluminum foil. (Yes, they could easily get through it if they want to, but it ends up mice really don't like the stuff and don't try.)

I had mice in my trailer the first winter I owned it, did this the following summer, and haven't had a single mouse in the trailer since.

Now if I could just figure out how to keep them out of my van!

If you have a slideout, check out where the linkage goes thru the frame.
Mine is like an open barn door for mice.
Check up front where your wires from the battery enters the underbelly.
Pat

a mouse only needs a hole the size of a pencil. get your spray foam out and hit every spot on the under belly.

Go over every inch of the underside. No space is too small to overlook. We found a small spot where OEM foam around brake wiring was knocked loose,(possibly a stray rock when traveling.) we resealed with foam and no vermin since. Use snap traps to remove those already inside.

WyoTraveler wrote:
Has your TT been plugged into AC? On my previous TT mice would just walk up the electrical cord and into the mouse hole especially made for them by the manufacturer. I made the modification with the Marinco type plug and no more mice in our TT. That mouse hole we pulled our electrical cord out of was just under the couch. Direct entry from outside. That is why they put rat shields on ships when they tie up in port. Mice and rats crawl up the mooring lines.

That's a very good point - thank you. It has been plugged in, and the evidence is in drawers next to the main circuit panel. It is definitely worth looking at.