It’s that time of year, when mice go rooting around for greener pastures indoors. After doing a couple of quick searches and my own recon, I’ve found the following as a winning combination of non-toxic (at least not the toxic-est of toxics) for keeping the mice at bay.
1) Repel vs. Kill – I go for repel. It’s better to keep the mice away than just kill them off because where there was one, there will be others. Mice aren’t like people in this regard. If we repeatedly see our own kind slain in the same spot repeatedly, we typically will steer clear. Mice, on the other hand, will just swoop right in where their brethren met their demise. So, instead of focusing your efforts on a losing battle, I suggest trying to make your abode the least inviting one around. Send the mice to your neighbors; hopefully they’re doing the same thing and eventually the little creatures will get the hint and check out some other blocks in your hood.
2) How to Repel – Mice do not like the following scents, and will steer clear if you keep these scents fresh and plenty:
a. Cloves & Cayenne. I first tried the cayenne, straight out of the shaker and into a small porcelain bowl (more of a ramekin), and set it under the sink near the dog food (which I transferred into an airtight container instead of just a pretty tight container) and the compost scraps (if you can handle keeping them in your freezer, that’s best but it’s pretty valuable real estate so we opt for a plastic container with tight sealing lid placed under the sink – no wonder mice had found their wonderland, right?). After I had wiped down and bleached this cupboard, and removed or transferred anything that might be seen as trappings of a mouse hotel, I went to the store (Foodtown) and bought my other artillery (see below). When I came back, the white Ikea fiberboard (nothing but fancy for me) that I had scrubbed spotless was now dotted with a trail of perfectly nuggety mouse turds. So, cayenne alone does not work. I then remembered what exactly you are supposed to do if you want to make spice fragrant so I threw some cayenne in a pan, along with the cloves I’d just got at Foodtown (returning the tiny bottle at $4.25 for the bigger bottle at $2.50 as soon as I came across it – lucky for us Thanksgiving is around the corner, and you should be able to find these mouse repelling spices on a tacky rack display at the end of any given aisle at your local grocer). I put the newly fragrant whole cloves and cayenne in a couple of ramekins and placed each in a corner of the cupboard where the mice were most likely to be making their entrance. This seemed, or truly has been, a success – at least in combination with a few other efforts listed below.
b. Bounce Fabric Sheets. Here is where the mice and I have something in common. I can’t stand them either but I went to Foodtown yesterday and took advantage of the special (two boxes for $5.00, which means I probably could have gotten just one for $2.50, but now I have one to spare to keep the critters away). I stuck these in various crevices where I thought mice might be making their way in – between gaps in cupboards and between the stove and underneath the microwave, etc. I don’t know if it needs to be Bounce per se or the generic will do – just make sure you don’t get anything fragrance free, of course. I went ahead and got Bounce because I don’t use fabric dryer sheets and if they didn’t work because they’re generic then I’d be SOL because I certainly wouldn’t be using them for anything else. Buying fabric dryer sheets is, to me, like buying Hallmark cards on one of the many “holidays” Hallmark created. It’s spending money on a fabricated (yes, intended) problem. When I got together with my current partner who doesn’t use fabric dryer sheets and never has, I was reminded why I got together with my current partner and followed suit.
c. Peppermint (maybe). I haven’t tried this one yet (since my neighborhood is gentrifying but not so gentrified that the nearest grocery store carries Dr. Bronner’s – it doesn’t). But given my aversion to Bounce and ammonia, this will likely be added to my cache of tricks and treats for the little critters. Or not. Just did a quick search and found mixed reviews about the efficacy of peppermint oil – some are saying use oil and not the extract, which is likely a la Dr. Bronner’s.
d. Ammonia. Word on the street is that ammonia to mice smells like the pee of their predators. Mice love the stove top, which really is the creepiest thing to me about them. I got a Home and Garden Sprayer bought cheap and made by mentally and physically challenged people in Michigan (seriously – they’re by Sprayco in Detroit, MI – support them and you’re supporting real work for the seriously marginalized in a locale that needs the dollars, also it’s a U.S. based family owned company that’s been around since the 1980s and its parent corp. started over 100 years ago – this is the kind of company I like). I filled it half full with ammonia, the rest with water, and I’m keeping it near the stove to spray frequently and liberally. Now, back to (or still on) toxicity, I’m really not sure which is more toxic – ammonia or Bounce. I’m seriously skeptic about what is going in processed/manufactured products — foodstuffs and others — these days. Yesterday in Foodtown, I couldn’t find good old fashioned steel wool pads, Brillo or otherwise, without them being doused in soap and bragging from box to box about how each had more soap than the other. Seriously, there were about five different styles, none of them soap free. (This is a different soap box topic – yes, intended – but I think sabon is way overrated, and the world would be a better place without it – and I’m no hippy dippy, free love, tree hugging, dirty hippy type although I probably admittedly have put my arms around a tree or two when no one was looking). All of which brings me to my last suggestion…
e. Steel Wool. This is a variation on scent/rodent repellant. It’s a barrier – mice cannot (or at least are not supposed to be able to) chew through steel wool. If you find that your little critters are chewing through this barrier, you may want to check out whether you’ve got mice or their more notorious cousin with the long tail. And if that’s your issue, you’ll need to check out a different site, one from a blogger who’s braver than me because if that were the problem, my list would be short and sweet, and consist only of a number for pest control. Other barriers that should work are aluminum foil (some say if mice step on this and hear it, it freaks them out because they think it’s the sound of another predator – Brooklyn mice are way too wizened for that, I suspect). Also, aluminum foil ain’t cheap, so it’s not really high on my list of recommendations.
3) And, in case repelling doesn’t work…
Good luck getting rid of the little beasties. I did set up a couple traps just as back-up. Animal cruelty? Maybe. But I also stomp any indoor centipede I meet, and don’t have the patience to shoo a mosquito or fly out the door. Since I am just as willing to hurt any other unwanted visitor to my house, I don’t feel too bad about it.
revelgardener 
I’ve never had (luckily) a mouse problem, just the occasional one who apparently took a wrong turn and got lost. The first thing which came to mind reading the title was CAT! Very effective, but they introduce other issues around the home. I’ve never owned a cat, but have spent some time around them. On the brillo, try going to a paint or hardware store. Aside from brillo, you can find steel wool in an assortment of thicknesses- no soap here. The course stuff packed into holes or cracks is a pretty good barrier. I suppose you can mix spices in with it, but unless you hear mouse sized chainsaws running you should be safe. I think size 0 is the course stuff, but it’s obvious if you see them side by side.
I’ve heard about ammonia smelling like pee to animals for a long time. I never looked into it. It may just be that the fumes are toxic and they are smart enough to avoid them. Ammonia is also corrosive so use it with care and avoid inhaling it.
From what I heard drier sheets deposit chemicals on your clothes which get absorbed through the skin. Again, no real research into this either.
I agree with the repel methods. Trapping or killing the critters is not the solution. Preventing them from getting in is the way to go. I wonder if mice would chew through expandable foam insulation?
A possible ‘techie’ idea would be to get an ultraviolet light of the correct wavelength to make urine ‘glow’. If you know a serious rock/ mineral collector they may have one. With some luck (?) you may see glowing spots or trails along their path- along with any pet’s past mishaps. I seem to remember a TV commercial for some cleaner where they gave you a UV light to see where to clean up after pets. I have no idea if the stuff was any good, but they are right about seeing urine with a UV light.
Interesting idea – would the purpose be to use repellant in more targeted spots by tracing their paths?
If you can find out where the mice are going you may be able to find out what is attracting them, or better yet where they are getting in. Try a paint or hardware store for steel wool. Among it’s uses is wood working. I’ve never checked but Home Depot may carry it. 0, 00, 000 should be the finer wool and I think #4 is the course stuff you want. When you see it you’ll know why mice don’t chew it. To them it’s like a mass of tangled razor wire.
From what I’ve heard, aside from obvious food mice will be attracted to things like soap, paper, and cardboard. If you find droppings look nearby for something they may have chewed into. They sell wedge shaped cardboard mice baits which you tear the top off (Mice B Gone maybe- can’t recall the name). Inside are small pellets the mice eat. It will kill them but slow enough that they will be elsewhere when they die. Those work, but will not address the real problem of them getting in.