Mice in the camper and why I hate mice!

As a family, we haven't been using the camper like years before. The weather this summer was either wet or hot it seemed. Between that and schedule conflicts, we didn't have any family overnights in the camper this summer. Boomer and I came out for day trips to get some work done and the entire family also came out for day trips, but not to spend the weekend. 

This lack of activity lead to mice moving into the camper. We haven't had issues before with mice, so this was a surprise. We've set traps and have removed a fair number of them but there is always more. I haven't been able to figure out where they are getting in either. I have blocked off places where I think they can get in, but it hasn't stopped them. We deep clean the camper, put in deterrents to try to make them leave, but it doesn't work. 

One thing I did notice that may be a part of why we have mice now is the neighbor. We have a neighbor, across the road and down a bit. He passed away last winter, but he was also the person who fed a bunch of feral cats. We would see the cats on the trail cameras at night coming and going, mostly around the camper. My guess, they were killing the mice around the camper and helping to keep them out. Since he has been gone, we don't see the cats on camera anymore and now we have mice. Maybe it's related, maybe not. 

Things got bad when deer season rolled around. I will spend some days in the camper hunting so I don't have to drive the hour + from our city house to the Estate. When I went up the first time, I got everything unpacked, cleaned up the mouse poop and wiped everything down. I then turned on the furnace. When the blower started, I noticed some "stuff" come out of one of the vents. I immediately knew there was a mouse-house in one of the vents. I turned off the furnace to keep from catching anything on fire until I could determine where the nest was. 

After disassembling the vents at the furnace, I found that the mice had built a large nest right at the heat exchanger inside the furnace. Good thing I turned it off, it for sure would have caught fire. Then, when I looked further into it, I found a lot of mouse urine and poop INSIDE the box for the heat exchanger. After I removed the nest and vacuumed out the heat exchanger box as much as I could, I turned on the furnace again. This time, the smell was overpowering! The mouse urine smell was so strong that I couldn't even stay inside the camper while it was running. This was bad. It meant I wouldn't be able to stay in the camper overnight until I had this issue resolved. 

Heat Exchanger Box Before Cleaning

I came back another day and removed the furnace from the camper to open it up and clean out the heat exchanger box. What I found was worse than I had expected. The entire bottom of the box was covered in urine and feces. I scrubbed and cleaned until I was pretty certain I had removed all I could. I reassembled the furnace and put it back in the camper to try again. I even replaced the heat ducting with new flexible ductwork since I knew the mice had soiled these as well. After it was all back together, I turned on the furnace again and while the smell was less, it was still very strong. I had to run into town for some stuff so I left the heat turned all the way up and I left the door and windows open hoping to air it all out as the furnace warmed up. After about an hour, it was a little better, but not all gone. When I left, I sprayed some disinfecting and deodorizing spray into the furnace box to let it sit while I was away. I am going to be going back up soon and will check on how the smell is. I also added some metal screen to the backside of the vents so the mice can no longer enter the furnace so easily. Time will tell. 

Heat Exchanger Box After Cleaning

Screens added behind vent to keep mice out of furnace

A big worry I have is about what happens when we close up the camper for the winter. We put a cover on it and don't enter for at least 4-5 months. Since I haven't figured out how they are getting in, they will have a long time to establish themselves before we go back in the spring. I am not looking forward to that.