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 (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. 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.
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.)