THE SNOW MELTS, revealing the horror: Mice and voles have had at it in your garden, coldframe or greenhouse. As fall approaches, maybe they’re scurrying for a nesting spot in your house or garage or shed. Whatever the havoc, mothballs are not the answer—and are in fact highly toxic, and illegal for garden use. Learn how to control rodent pests safely, and how mice in particular figure into the Lyme-disease equation, too.
Though this is not new information, it apparently bears repeating. I hear from readers whenever I mention animal control–even of deer–who share the “tip” that they’ve discovered mothballs, reporting that they have spread them in a vole-besieged bed, or along their deer-pressured property line, or even in a stone wall, perhaps, to deter snakes.
Any use not specifically listed on the package violates Federal law, and can also harm you, your pets, or animals in the environment, and can contaminate soil and water, according to the National Pesticide Information Center at Oregon State. Moth balls do not belong in your garden (nor in your attic, car, or crawl space).
Moth balls (and flakes) contain either napthalene or paradichlorobenzene. I frankly don’t want them in my closet, either, even inside a closed container as the directions advise, but again: Anywhere else is illegal, and dangerous.
What to do instead?
For rodents, I follow longtime organic farmer Eliot Coleman’s advice and trap year-round in key garden areas and outbuildings, placing my traps inside homemade boxes, as in the photos above and below. I like the Snap-e brand of trap (affiliate link), shown, for ease of setting and lastingness. Get the whole story on the boxes and how to use them. The box protects other animals from potentially getting injured, compared to a trap placed out in the open. I bait mine with peanut butter, because most of my prey are mice; Coleman uses no bait for trapping voles. I get voles, too, even with the bait applied.
the mouse-lyme disease connection
GARDEN DAMAGE ASIDE, I also aggressively trap rodents year round near the house—my own primary habitat!–because white-footed mice, in particular, are a primary vector for Lyme-disease transmission.Ticks that feed on mice are particularly likely to become infected with the spirochete bacterium implicated in Lyme.
“Long-term research shows that white-footed mice are the critical hosts for black-legged ticks, which carry and spread the bacterium that causes Lyme disease,” says the Cary Institute in Millbrook, New York, where extensive tick-related research is under way. Read their summary on the ecology of Lyme disease for a shorthand insight into this disease and its life cycle. “Superabundant mouse populations allow more ticks to survive and lead to predictable spikes in human Lyme disease exposure.” Scientists there are even working on a bait that could inoculate mouse populations against the bacterium.
So-called “deer ticks” usually spread the Lyme to humans as nymphs, their second life stage—and the stage at which they are more likely to be on mice or shrews (or perhaps even chipmunks) than on deer, who are more often hosts for the adult ticks.
My own vigilant “mouse patrol,” as I refer to it, may be slightly irrational–clearly, I am not capable of achieving a truly mouse-free zone. But letting their population build up unnecessarily where I am most likely to interact with them is something I prefer not to do.
One final thought about those snakes, and by association, those mice and voles:
Snakes are one of your best allies in garden pest control, with many species consuming not only rodents, but also those garden-damaging pests, slugs. A healthy garden includes snakes as part of its community, and though I may at first feel squeamish when one startles me outside, I am glad they’re here and would never harm one. Red-tailed hawks, who also like to pick off small animals like mice, racing down from the sky with more precision than any mousetrap I could employ, agree with me that snakes are great, but for another reason. They like to enjoy the occasional snake for lunch.
It’s a food chain; don’t poison it with mothballs or any other chemical. (And there are even more players in the dance, of course, than my little example above.)
Oh, and want to keep deer out? Get a fence. No kidding.
more on voles (vs. moles) and ‘nuisance wildlife’
CAN’T TELL signs of a vole from a mole, or have other “nuisance wildlife” issues, from rabbits to woodchucks to who knows who? This interview with Marnie Titchenell from Ohio State University may help. (Above, photo of voles’ surface tunneling in turf from Missouri Botanical Garden, where they have more on voles and mice.)
Mice in the house and voles in the gardens have become a big constant problem especially since I don’t have a cat anymore. When I had a cat the mice and voles stayed away.. I use traps now similar to what you do in house – have to make boxes for outdoors
When we moved to the high desert in northern New Mexico, I started gardening. Keeping it small because of scarce water, I nurtured out little plants. One morning we went out and found that the entire thing had been decimated. Rabbits got it from above, and pocket gophers got it from below. I was horrified.
We tackled the problem from below and from above. I “planted” hardware cloth below the beds, and surrounded the garden with fencing. I put chicken wire up the side of the fence about 18 inches. That has kept the creatures out of my garden – as long as I remember to close the gate!
Forgot to mention – we keep the mice down with barn cats, compliments of our local Humane Society. They also do a pretty good job of keeping rabbits out of the yard. Without an abundance of mice, the snakes stay away.
I’ve had a rough time with big ugly intelligent rats. I plugged up all visible holes to my house foundation using steel wool, but they were still getting under the house and inside my kitchen. Mechanical traps didn’t work. Sticky traps didn’t work. Electric shock traps didn’t work. (The rat or rat(s) figured out how to open the back door where the peanut butter was placed without going inside the trap.) Poisoned baits didn’t work. They wouldn’t eat the bait.–I didn’t want to use these, but felt I had no choice. (I garden for wildlife which includes the predators that eat rats.) The rat(s) got into my pantry and tore into my sugar, flour, beans, and rice. I put all in canisters, but the rats still came in. I finally cleaned up my old small live trap and after two unsuccessful tries, caught two rats. I let them go in a wild area outside of town. Hope they don’t return.
I do something similar to trapping mice in the garden and around the outside of the house and sheds. I take those sturdy black pots that you get from the garden center and put a trap in the bottom and cover the top with a heavy saucer. If the saucer is not heavy, I add a rock or brick on top. The holes at the bottom of the black pot are just big enough for the mice. My neighbor uses the regular hanging basket planters turned upside down with a rock or brick on top. These two set ups catch a lot of mice quickly.
Some of the mice that make their way into my kitchen (the stove) manage to outwit the mousetraps you like. Sometimes they get them but just as often the peanut butter is gone without springing the trap. I’ve concluded that mice are very smart.
I currently have a swollen right knee from Lyme disease. That led me to read Nicholas Baker’s book, Baseless, about the US government’s Cold War era weaponization of insects programs & Kris Newby’s book, Bitten, specifically about how ticks were weaponized to carry and spread Lyme, babesiosis, etc. Absolutely horrid ends-justify-the-means science experiments that we’ll all be paying for forever with our health and health care budgets. And possibly pertinent to our current zoonotic pandemic.
Lady Margaret, your ideas for dissuading mice & voles are of interest, but for me, with a dozen cats, my problem is a family of raccoons, maybe 7, who are rampaging my urban neighborhood–older homes of 1940s on small acreage-1-2 acres. The raccoons have learned to literally climb the sides of my frame two-story house, even clawing in footholds like mountain climbers! Then they crowd around and look eagerly in my upstairs windowpanes! (No, I don’t feed cats on porches or outside.) The Raccoons even broke one pane, scampering like clowns down the hall—aghhhh! Window is, now repaired, but their assaults are more than spooky. I DO NOT Want to kill them by poison or traps, but I do want to insist that they GO SOMEWHERE ELSE!! I will pay for their bus tickets!
Martha in Blue Skies Texas
So… I put a hardware cloth fence that’s dug into ground around my veggie garden to deter mice and voles… I am concerned now that the snakes can’t get in to get any mice/voles that may penetrate the barrier… does hardware cloth help or hinder?
Have you heard about Mouse Magic? It’s all herbs and comes in sachets (little stitched closed cloth bags). The mice don’t like the herbal smell so they don’t stop. I use them in the garage (our indoor only cats still go out there hoping), tool shed and pump room. No signs of mice.
That’s great, Janice. Here in rural farm-country Nowheresville in an 1880s house w/stone foundation … oh my. I bet those sachets are good for the tractor engine compartment and other places they like to hide in winter …
I had traps in my potting room, but after killing 2 chipmunks : ( no more. I still use them in the basement and now keep bird food in metal bins. Sorry mice.
I haven’t seen a slug in quite a few years since a really big Garter snake and a couple smaller ones have been around each summer.
Thanks for your good suggestions regarding mice and voles.
Do you have any suggested stratefgies for keeping WOODCHUCKS at bay???
A little discussion of that in this other story. They are hard to “exclude” from a whole garden unless you also do serious underground hardware cloth/wire as well as above-ground, but eliminating desirable easy places for them to move into (under a stoop, porch, etc.) with a little carpentry or mesh barrier is advised. Most of us live-trap them according to the laws in our local area, sometimes with the assistance of a DEC-licensed nuisance wildlife handler.
Say no to coyote urine repellants, too.
Racoons are digging up lawns in our Vancouver, BC area to find chafer grubs so participants in a popular Vancouver Facebook garden chat site keep recommending coyote urine- based deterrents. The SPCA strongly recommends against using these products because of the cruel way coyotes are kept to collect their urine.
The companies who produce these say they are kind to the coyotes they keep- don’t trust their word; if you actually stop to think about how these poor animals would need to live so their urine could be collected, you know there is no humane way to keep them.
I am surprised ultrasonic devices are not mentioned in the review? My neighborhood maintenance company mgr uses them as well as my garden designer friend. I plan to try them as a new development is sending me voles and nice.
Their effectiveness has been such a passionate matter of dispute (including the FTC requiring warnings on packages starting almost 20 years ago) that I just don’t have the expert judgment to recommend them.
Margaret, your article is well reasoned and very helpful with a good understanding mouse behavior. I have extensive experience in commercial pest management. In addition I have been an organic gardener for many years. For residential settings, the use of good quality snap traps is essential. Finding points of entry into a home is sometimes challenging. A point of reference: entry points, mice need only 1/4″ and rats 1/2″ . Closing holes once you find them is effectively and permanently done using copper gauze stuffed into the hole ( available at hardware stores and Amazon). If traps are not working, try different baits. I often use Reese’s pieces. Many mice like chocolate. Rats often respond to odiferous fish, like sardines. Be careful to place baits using gloves . Rodents are very sensitive to tobacco and fragrances and will avoid them. Once trapped, wear gloves when handling the trap. Rodents carry ectoparasites besides ticks.
I am concerned about snap traps. Caroline wrens often get in my Havahart mouse and vole traps. I started using them after catching one in a snap trap. Even with them you have to check every day because they will die of dehydration if you don’t set them free fairly quickly. I know I have one when I hear the trap rattling. The wrens bounce around inside the traps; the mice or voles sit quietly.