After a full spring and summer, your lawn is looking great. The soil is healthy, and that thick green turf covers your yard like a carpet.
Unfortunately, you may as well be setting out the buffet table for pesky grass-eating voles.
That beautiful lawn is prime feed for the small rodents.
“It would be a really rich area for a vole to discover,” says Dana Sanchez, a wildlife specialist with the Oregon State University Extension.
They’ll move in, cut tunnels through your lawn and snack on your grass until they’ve cut roads through that perfect lawn.
Not to be confused with carnivorous moles, the Penn State University Extension describes the herbivorous voles as “small, chunky, ground-dwelling rodents.”
What Voles Look Like
When mature, they measure 5 to 7 inches with stocky bodies, short legs and short tails. While young voles are uniformly gray, adults are chestnut brown mixed with black, but their underparts are dark gray. They have small eyes and their ears are furred and don’t project much. (The scientific name of the North American genus of mole, Microtus, refers to their small ears).
As the Colorado State University Extension notes, different species of vole are spread far and wide. Colorado alone hosts eight species of voles, which are often called meadow mice or field mice. Prairie voles, meadow voles, montane voles and sagebrush voles are among those that make their homes there, and other species are spread across the country from Alabama to Oregon.
In Oregon’s Willamette Valley, there’s even an endemic vole species, the gray-tailed vole that evolved there, says Sanchez. It’s a strong habitat for voles, which give area homeowners plenty of headaches.
“Are voles mice? Definitely not!”, commented professional exterminators Fantastic Pest Control UK. “Voles and mice are rather cousins than brothers or sisters”, the experts add.
Regardless of their names, voles do lunch on home lawns causing vast areas of hard-to-fix damage.
“For people who are very much wanting that ‘show lawn,’ it could potentially be a severe problem,” Sanchez says.
It’s not just your grass that voles will eat. They also girdle young trees and other woody vegetation by gnawing around the plants’ bases, says the University of Nebraska Extension.
The damage to trees and other ornamental plants is worst in the winter when voles don’t have much else to eat.
How to Tell if It’s Vole Doing the Damage
Voles leave unmistakable scars in your yard called runs or runways — grassless depressions crisscrossing your yard like little sidewalks leading to and from their burrow openings. Aside from setting eyes on the animals, those runway systems are how you know you’ve got voles.
As an article from the Penn State Extension explains, voles don’t hibernate. They stay active day and night, even when your yard is under 2 feet of snow.
Once the spring snowmelt comes you will start to see any evidence of winterkill — the blanket term for all sorts of damage caused by the cold. If no runways from burrowing are readily available, but you still suspect a vole infestation, go ahead and mow your lawn.
The vole tunnels — small, 1- to 2-inch runways — should be visible after that first mow. They can be completely free of grass, or look like miniature grassy ditches.
If you see mold or vegetation springing up in runways or burrow entrances, that’s good news. It means the critters have moved on.
If the damage is to your trees or shrubs, the Colorado Extension says there are some other tell-tale signs of vole damage.
If it’s voles, you’ll see patches of gnaw marks with irregular patterns about 1/16th to 1/8th inches wide.
Gnawed stems may have a pointed tip, and the roots or tubers may also show the same wear.
But voles don’t need snow for cover, explains the University of Maryland Extension.
They’ll also burrow under leafy cover or excess mulch, use underground tunnels left by moles (which eat insects such as earthworms underground) or gophers (which eat bulbs and roots), and burrow under pavers or stepping stones.
Some Stay Hidden
And not all voles play by the same rules. One species, pine voles, burrow entirely underground. Their damage may not be as easy to spot, but they still have their tells.
Spongy ground from their tunnels will give them away, and trees that seem to be suffering from other problems may be getting girdled underground by pine voles.
Even hawks circling overhead can be a clue that you have voles in your yard, says Colorado State.
Voles Come, Voles Go
Sanchez notes that vole populations are cyclical. Their populations wax and wane.
And while it is tied to food supplies, no one has been able to crack the code in predicting when the next high population year will be. This has also given people the wrong impression that voles have completely gone away in years of low population.
Voles Extermination: Traps, Baits
So it’s voles. If you want to protect your lawn from further damage, it’s time to evict those unwanted squatters. That usually means trapping or toxic chemical bait.
But due to the sheer number of voles present in many areas, those approaches can be so labor-intensive they’re futile, says the University of Massachusetts Extension.
Couple that with the normally short-lived damage that voles cause to turf, and the UMass Extension says such methods are rarely recommended for residential lawns.
Tips for Baiting Voles
Chemical baits are an option, but they must be used with caution. They can also poison other animals, including birds and small mammals such as squirrels and chipmunks.
Despite the downside, the Nebraska Extension says that toxic chemical baits are the most-effective way to reduce large vole populations.
Here are some tips before you set out to bait your yard:
- Be sure to read all product labels. Some pesticides, such as zinc phosphide, require licensing, Sanchez says. It may be best to call in the pros.
- Apply the baits during the late fall and winter when voles have a diminished food source.
- Check stations every other day early on to make sure there’s enough bait available.
- Pre-bait with oats or seeds before using certain toxicants, which can have a bitter taste.
One less-intensive option, though, is the classic spring-action mousetrap. It’s effective, but often doesn’t significantly reduce populations.
Snap-trapping, as it’s known, is best for small areas says Sanchez. With a relatively small lawn, a quarter-acre to a half-acre or so, trapping can be effective.
“The larger the area, the less feasible snap-trapping becomes,” she says. It comes down to how much time people can afford to invest in the effort.
The Nebraska Extension offers some guidance:
- Place the snap traps perpendicular to the surface runways.
- Bait is not necessary, but peanut butter mixed with oatmeal is a good option.
- Cover the trap with a box with a 1-inch hole cut in it to reduce catching birds or squirrels. But make sure it’s big enough to allow the trap’s snapping action.
Multiple-catch mouse traps are also a good option, the extension says. They allow you to catch more than one vole at a time and are especially effective for meadow voles and prairie voles.
Bait them with birdseed or grass seed at both entrances and check them after 24 hours. You should have caught a few by that time. If not, move the traps to new locations.
But as with most pest control issues, an integrated pest management approach will be the most effective.
Most problems in home lawns can be mitigated with a mix of habitat changes like fencing or exclusion, trapping and repellents.
Your best bet at controlling voles is making sure they never take up residence in the first place.
And one “excellent avenue of free vole control,” says the UMass extension office, is an open winter without snow. Vole activity on exposed lawn areas is greatly reduced without the relative protection of snow cover.
Cleaning Up Voles’ Mess in Lawns
If voles have cut runways through your yard or maybe tunneled under your turf, don’t worry.
The University of Nebraska Institute of Agriculture and Natural Resources says that vole damage to lawns usually repairs itself when spring growth ramps back up, and is not permanent.
Damage from voles is costliest when it occurs on woody plants. Girdling caused by gnawing voles can severely damage or kill desirable young trees and shrubs.
To give your lawn a kickstart in early spring, though, Colorado State has some tips. Simply rake, fertilize and water the affected area. Those vole runways should disappear beneath green turf in no time.
Preventing Damage: Habitat Modification
The best way to control vole damage is to make sure they never set up shop in your lawn in the first place.
There are several ways to keep the little varmints out, especially closing down the buffet table. You definitely don’t want to get rid of the lawn, but other grassy plants can go.
- Trim up tall grass and weeds around young trees.
- Move or remove bird feeders. They may give the voles a free lunch.
- Limit grass. Grass is voles’ preferred habitat, and if you can get creative with your landscape you can remove that option. Voles, ever fearful of predators, are less likely to cross a weed-free area at least 15 feet wide. “Do you need to have lawn or grass there?” asks Sanchez.
- Mow close in the fall before the snow arrives. Lower the lawn reduces its attraction for voles. The UMass extension recommends mowing extra close that last time.
- Move wood or brush piles, compost piles and other ground cover well away from the lawn.
The next step is exclusion: installing physical barriers to keep voles out.
You may have seen big plastic pipes at the base of trees or shrubs in your neighborhood. This, as well as tree wrap, hardware cloth or other wire mesh will protect from vole damage.
To protect an individual shrub or tree:
- Cut a section of pipe or form a plastic cylinder, making sure there are no gaps.
- The cylinder should be 18 inches higher than the maximum snow depth in winter.
- Make it tight to the ground or slightly bury it.
- Cover the tops of the tubes to keep from trapping small birds.
A mesh fence can also protect your prize flower beds, gardens or other sensitive areas. For very small garden beds or other areas, Sanchez says, exclusion like this can be effective to keep voles from burrowing into them.
For best results:
- Use a quarter-inch or smaller mesh.
- Bury the bottom of the fence two to three inches beneath the surface.
- Make sure the fence extends about a foot above the ground.
Repellents mark your yard as a no-go zone when voles go sniffing around for a new home.
This can be everything from manufactured repellent chemicals such as the fungicide thiram, or more organic options like capsaicin, the ingredient that makes spicy foods spicy, says Penn State.
But the extension caveats that not much data exists on the effectiveness of these repellents, and they shouldn’t be your only tactic in controlling voles.
Sanchez doubted the effectiveness of repellents, saying the first concern with using them is where the voles would end up. Would it be in your neighbor’s yard or just somewhere else in your lawn?
To prevent the voles from forming a feeding pattern, apply repellents before the damage becomes significant, or before it occurs at all. Apply the repellents around trees or shrubs you hope to keep free of voles, but make sure not to apply them to any portion of a plant that may be consumed by a person or pet.
Speaking from her experience with excluding deer from yards, Sanchez recommended mixing up the repellents, especially if they base their vole-appeal on taste or scent.
Animals quickly habituate to bad smells or tastes, so mixing it up every six weeks or so keeps repellents more effective.
Keeping an Eye Out
Unfortunately, lawns are voles’ habitat, so long as you keep growing grass, you’ll keep attracting voles.
“It’s a matter of people recognizing the signs of voles if not seeing voles themselves,” Sanchez says.
The decision is whether to exclude the voles and how to do it. Continue to monitor the yard, she says, walking around the perimeter to look for signs of voles.
“It’s likely that the area will be rediscovered by more animals, so there is no one and done solution to simply eliminating the animals,” Sanchez says.