battling mice and voles (but never with mothballs)

mousetrapsTHE 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.  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.

box for mousetraps

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 (I like the Snap-e brand, shown for ease of setting and lastingness) inside homemade boxes, as in the photos above and below. (Get the whole story on the boxes and how to use them.) I bait mine with peanut butter; Coleman uses no bait.

box mousetrap with lid offthe 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. “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.

garter snakeOne 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 am 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.

March 20, 2014


  1. kathy says

    My husband and I can’t stand to kill anything so he traps rodents in “have a heart” traps and releases them miles deep into the woods! We live in a climatic forest and have lots of hawks and snakes.

  2. Cene says

    Voles… I have a city. Kitty kills at least 3 a day. I would never in a million years thought to use mothballs. Or traps. Mainly have to clean the leaves up so they don’t have a place to hide. But … Ive noticed they have very discriminating taste when it comes to the plants they like to eat. Only the expensive ones…. On the bright side- They seem to aerate the grass ? ( I know… no bright side to voles ) My snakes are the best fed on the whole street ! Love to see their vole eating selves !

  3. Diane says

    We had the most wonderful rodent catcher this winter, a bobcat! It was amazing to watch her follow her prey moving under the snow then suddenly watch her pounce breaking the crust of the snow and most of the time successfully capturing a meal! Beautiful creature. Another of the many reasons not to use pesticides or poisons.

  4. Pam Hinckley says

    I have found a delightful mouse trap to use in my cellar (I also have a very old house). I take a 5 gallon bucket, add 3″ of water, smear peanut butter along the inside of the bucket, and add a piece of wood about an inch wide as a ramp. Mouse smells the peanut butter, fall s and drowns. To dispose, dump water and mouse outside and then add more water. While it won’t work outside, it does help protect the veggies in the root cellar. I have caught more than a dozen mice this winter.

    • margaret says

      Hi, Patricia. Moles are great soil aerators, and eat some grubs (and also earthworms)…they don’t eat plants (though sometimes their tunneling disrupts things). So I like them, but of course anything in excess can be tricky. Sometimes it’s written that having loads of grubs (such as those of Japanese beetles) makes the turf or garden more appealing to moles, but again: they really love earthworms, so getting rids of grubs won’t solve your problem, other experts say. Ohio State has this point of view; at UC-Davis this is the wisdom. As you can see trapping is what’s recommended if control is really warranted. I’d recommend against wasting time on home remedies like castor oil and definitely not to buy and use toxic baits and fumigants.

      • Pat Olson says

        Thanks. My property is loaded with earthworms in the nice-looking soil. My biggest issue with the moles is the holes I trip in all over my property as my dachshund attempts to uproot the poor critters!

  5. Maggie says

    What kind of peanut butter actually works? I must be using the wrong kind because my traps sit untouched for months, while other evidence of mouse activity appears. I used the 365 brand from Whole Foods, just because I had it. I used to use the fluff inside the Cadbury Creame Eggs, but since they changed the formula, that doesn’t work, either.

    • margaret says

      Hi, Maggie. I have used the junkiest supermarket generic brands that I would never eat myself, and gourmet stuff, too, when I had nothing else. It all works. You have to freshen the bait every few days; it does not stay fresh (and can even mold/harden). Try sticking a sunflower seeds or two onto the dab of PB perhaps. But the trick isn’t the brand, that much I feel certain of (and I have even used leftover almond butter, by the way).

    • says

      Add a little jelly and a piece of pretzel to the peanut butter. My Va. mice seem to prefer a “sandwich!” (but to refresh it lest it get moldy…)

  6. claudia says

    I have an old PB jar (gone rancid) that I use as mouse trap bait. Many of the newer plastic snap trpas are so fast that the PB is never touched and will last a season (and still catch mice)! Just label the jar as MOUSE with a sharpie. Wouldn’t work around non-readers.

  7. Tammi says

    We use a trap on our backyard rats (they love birdseed) remove them from the trap and leave them on the lawn overnight. They are always gone by daybreak. Lots of owls and hawks to dispose of them. Why we won’t use poisons!

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