How do I get rid of a mouse in my wall? Sub-zero temp edition

December 23, 2017 10:12 PM

Last night we heard a mouse (?) scratching in our bedroom wall between the drywall and the exterior siding. This morning we plugged two suspicious holes along our foundation/window frame with steel wool. The scratching resumed tonight. What do we do?

We are headed for a couple days of sub-zero temperatures in Minnesota. If we succeeded in trapping the mouse in the wall and it dies, will it start stinking? Or will it freeze and then start stinking in the spring? Should we take out the steel wool from the holes in the wall and try to put traps in the rocks and snow along our outside foundation in case the mouse does decide to escape? What kind of bait would work in freezing temperatures?

All I want for Christmas is to sleep in peace again.

posted by Maarika to Home & Garden (11 answers total)

I've had an exterminator set poison bait in the attic and the cellar. When it died in the walls, the smell only lasted two days or so. I think of it as the smell of victory. That little bastard was under my pillow when I went to bed one night.
posted by TWinbrook8 at 11:01 PM on December 23, 2017 [2 favorites]

That little bastard was under my pillow when I went to bed one night.

The look on my face as I read those words defies description. As does the sound that came out of my mouth.

Recovering from my horror, you might want to unplug one hole and put one of those large covered traps against it so if little Jerry leaves via that hole he'll have nowhere to go but into the trap. If you are the humane type you could get a catch and release one. If you are like me, get one of the tomcat ones. Otherwise TWinbrook8 is right. Sometimes critters die in the walls and the price we pay for not having to deal with the ick is a smell for a few days.
posted by Homo neanderthalensis at 12:16 AM on December 24, 2017 [1 favorite]

Best answer: I recommend the Havahart X-Small 2-Door Trap (model#1020). It is a live trap that is very effective when baited with peanut butter. When we have used them in the past, we released the mice outdoors well away from the house while singing Born Free.
posted by fairmettle at 2:35 AM on December 24, 2017 [8 favorites]

Best answer: There's a good chance that there are multiple ways for the mouse to get out of the wall and into your house or into the outside world. Mice can fit through very small cracks. It's probably not trapped just because you plugged up the holes you could see. I would set a trap, or several traps, inside the house because that's easier. If the mouse can get into the main part of your house (and I would assume it can) it's undoubtedly roaming all through it looking for food and will find the trap. Peanut butter makes a good bait and should work fine in freezing temperatures if you want to set a trap outside.

If you use a live trap, release the mouse farther away than you think you really need to, at least a couple of miles. They can travel pretty far. (It may feel better to release the mouse alive, but the average mouse doesn't live long even under the best of circumstances and one that has just been released into an unfamiliar area in winter is even more vulnerable, so you're not necessarily doing it a favor.)
posted by Redstart at 5:42 AM on December 24, 2017 [6 favorites]

Well, it you don’t feel like killing anything for Christmas, but want it gone as quickly as possible I have found sticking something with tea tree oil in one of the holes does the trick. I believe peppermint oil can work as well. It was my instant fix a few times. I was surprised how well it worked.
posted by Vaike at 12:10 PM on December 24, 2017

If you wish to conduct an ethical assessment prior to deciding your mouse's fate, wikiHow provides a number of options in How to Humanely Kill a Rodent. Despite live release being disavowed by PETA and the RSPCA, wild animals are born survivors and you may still want to consider giving them a long shot chance at living.
posted by fairmettle at 4:27 PM on December 24, 2017

Best answer: There's a better than even chance you have more potential holes than you've found, and more mice as well. We had mice move into the garage last winter when birdseed was out & open and I had to set out traps. Thirteen mice later we prevailed. Once under siege, mouse = vermin mindset rules, and we didn't want the cats eating wild critters.
posted by Pressed Rat at 6:12 PM on December 24, 2017

Response by poster: Thanks for the tips, everyone. Our basement was sealed completely with hard core spray insulation a couple years ago after we had to gut it after a flood, and we have never seen any evidence of mice upstairs. So for the time being, I really am quite sure that they are just in the wall for now. We actually drilled a hole in our bedroom drywall where we've heard the most noise, taped a box to the wall, put traps inside and around the box, and made a view window out of Saran Wrap. Hopfully the mouse will try to find a warmer spot inside and meet its demise.

After the hardware store opens post-Christmas I will get some live traps for outdoors along the foundation. If all else fails, I will go crazy with tea tree oil and try to borrow a neighborhood cat for a mouse reconnaissance mission. Wish us luck.
posted by Maarika at 8:07 PM on December 24, 2017 [2 favorites]

Best answer: If you use spring traps, especially the classic wire and board ones, make sure to use peanut butter and really work it well into the holes in the center of the trigger plate. You want to make sure that the rodent needs to apply pressure to the plate effectively to access the food. This is the difference between success and failure for spring traps that I have found.
posted by Ferreous at 10:26 PM on December 25, 2017

Response by poster: We found 3 mice in the kitchen this morning: 2 in traps, 1 sitting on the trap eating peanut butter and mocking us. I marked best answers that gently pointed out reality rather than the fact I was in denial. The battle continues (and my son may end up getting his wish of a household cat after all).
posted by Maarika at 12:26 PM on December 26, 2017

Response by poster: Final update: I found and plugged the entry point (mice chewed through a plastic cover to our basement bathroom exhaust vent and propped the flapper open with maple tree seeds and fur). We killed 3 mice in snap traps in our kitchen, zero in the box of death taped to the wall, and one twice in a live trap outside (I dropped the trap and watched it scurry away; the next time I drove it in my car and set it free on the other side of a lake). It took about a week from initial invasion to eradication.
posted by Maarika at 8:47 PM on February 3, 2018