Moles and Voles
Shawn Weeks, Wildlife Management Specialist, believes that moles and voles are indeed a lawn and garden pest. However, he also says that wild animals are part of what makes nature so magical. While it’s important to coexist with animals in relative peace, they can cause many problems when they live in our lawns and gardens with their tunnels.
It seems every time I plant something new, within a day I see a raised tunnel heading straight to it; but many times there is no damage. In fact, a part of my yard near our pasture has grass that is not well manicured. When I feel lumps in it that I cannot see, that lump is actually a tunnel, and I do nothing. My garden, however, seems to constantly have these “runs” — especially in mulched areas. Most of the time they cause no damage, but in some mulched beds, the tunnels actually raise up the soil under a plant as the pest passes through, making an unsightly bed. That is this year. However, in the past I have seen several young edamame plants literally disappear below the soil surface. It reminded me of a cartoon where the gardener tries to hold onto the vegetable and the pest tries to pull it under.
Other than having similar names, voles and moles have little in common. They are two entirely different pests, yet they’re often confused. Moles are better known, but it may actually be a vole causing damage especially in gardens and flower beds.
Identify the culprit
Moles are 5 to 7 inches in length, gray to dark brown in color, and are mammals. They are NOT rodents. They have a long, naked snout, no external ears (who wants dirt in your ears?) and can tunnel 1 foot per minute. Their eyes are buried in their fur. They are rarely seen because they live and feed underground, preferring moist, loose soil. Since they don’t eat plants, their landscape carnage is really the incidental damage of shallow tunnels and runways dug in lawns searching for food. However, tunnels may cause damage to plants when their runways create paths around roots. Another objection from gardeners and those mowing the lawn is dirt that is mounded up in a rounded volcanic shape — better known as a molehill.
Voles are rodents — looking much like mice with shorter tails. Voles are usually 5 to 7 inches long and may be black, gray or brown. They have eyes and ears that can be easily seen. Voles can either burrow, or more likely, use old mole tunnels. Between burrow openings, they produce characteristic surface runways about the size of a broomstick that you can see. They stay in nests above ground, coming out to eat day and night at short intervals.
The mole’s diet is almost exclusively earthworms and grubs, with a few insects for appetizers.
Voles, on the other hand, are plant-eaters or herbivores. They feed primarily on grasses, flowers, vegetables, bulbs and seeds. In the winter when food is scarce, they may eat bark off of trees and shrubs.
Moles are anti-social mammals, seeking each other out only at mating time. This means that usually you should only have 1 or 2 moles in your yard. There are generally 4 to 7 per litter. Their life span is 2 to 3 years.
Voles are prolific reproducers that can quickly colonize your yard. Their life span is only about 16 months or less, so they have to make up for it by having 3 to 6 young at a time with only a 21-day gestation period! Because they reproduce quickly, eat so many things, and are good at hiding, they can do a lot of damage before the gardener figures out the problem.
Ignore or combat the problem?
First, let me say that moles can be beneficial because they consume large numbers of grubs. Their tunneling can also aerate the lawn and mix deeper soil with surface organic material. Other than that….they are a nuisance!
I honestly can’t think of any benefits to having voles in your garden and lawn. The control methods for both moles and voles is quite similar, but there is no one-and-done solution. In fact, we have few reliable approaches that will provide long lasting relief. I would encourage the use of only scientific research — not the many gadgets and homemade recipes that you may find.
So the important thing is to asses the level of damage and the level of need for control. Is having a few holes in your yard or perhaps some limited plant damage sufficient grounds for action?
Only Live Traps
Trapping, although successful in catching moles, should be viewed as a temporary fix. If the area continues to have the food supply they are looking for, more than likely others will come in to replace the one you removed.
To live-trap moles, use a can about 10 inches in length and 6 inches wide and place it vertically beneath the tunnel. The top of the can is level with the bottom of the tunnel. As the mole comes along the runway it drops in unable to get out and can then be relocated.
Due to the large population of voles, traps are NOT very effective and are probably only a temporary control.
Repellents & Barriers
The most common repellent for moles contains castor oil and is registered for use in Virginia. It comes in the form of pellets or can be mixed and sprayed on the lawn, lasting as long as 6-8 weeks.
A barrier can be used around planting beds to deter the voles and moles by mixing something sharp into the soil. This could be sand, gravel or a products that are similar to cat litter. These materials, once they are mixed into the soil, make it more difficult for the pests to navigate.
Another barrier is the use of sheet metal or hardware cloth placed around the affected area. To install this barrier, dig a trench 12-15 inches deep and 10 inches wide. Place 8-10 inches of the barrier in the trench and then fold the remainder upright to create an “L”. It should extend about 5 inches above the ground for complete protection. Backfill the trench with soil.
Limit food supply
Since grubs are the main source of food for moles, treating for grubs is an option. See last month’s article on grub treatment. However, the Virginia Tech Extension Office believes it really should be viewed as a grub treatment rather than mole control . Of course, moles love earthworms — as do gardeners — so we do not want to do anything to deter earthworms.
Voles make their hidden nests in vegetation and brush, so avoid having brush piles and the like near the areas you want to protect. Lastly, mulch is also a great place for voles to hide, especially if applied too thickly. Use a minimum of mulch around areas you need to protect.
No fumigants or toxicants
As with all wildlife, non-lethal control measures should be exhausted before lethal measures are used. Poisons are not recommended and may not only kill these pests but could even harm other animals if theycatch and eat the mole or vole after it has ingested the poison but before it is dead. Fumigants and toxicants are restricted in Virginia to certified pesticide applicators.
In Virginia it is illegal to:
- set a trap where it would be likely to injure persons, dogs, stock or fowl � 29.1-521
- not visit all traps once each day and remove all animals caught � 29.1-521
- transport, release, or relocate a mole anywhere other than the property it was caught on 4VAC15-30-50
- poison any animal (including moles) other than rats and mice on your property 4VAC15-40-50.
Pesticides (which include herbicides, insecticides, rotenticides, etc.) are poisonous. Always read and carefully follow all precautions and safety recommendations given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed, away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Consult the pesticide label to determine active ingredients, signal words, and proper protective equipment.
Pesticides applied in your home and landscape can move and contaminate creeks, lakes, and rivers. Confine chemicals to the property being treated and never allow them to get into drains or creeks. Avoid drift onto neighboring properties and untargeted areas.
Parkhurst, Jim, “Moles and Voles,” Virginia Cooperative Extension Publication, http://www.ext.vt.edu/topics/lawn-garden/turfgrass/turfandgardentips/tips/mole-vole.html
“Identifying Moles, Voles and Shrews,” Penn State College of Agricultural Sciences, http://extension.psu.edu/natural-resources/wildlife/faqs/nuisance-damage/identifying-moles-voles-and-shrews
Pokomy, Kim, “Moles, Voles and Gophers Dig the Garden,” Oregon State University Cooperative Extension Publication, http://extension.oregonstate.edu/gardening/2015/04/moles-voles-and-gophers-dig-garden
Weeks, Shawn, “Pests of the Month: Moles and Voles,” Home and Garden, May 16, 2011. http://farmersalmanac.com/home-garden/2011/05/16/pest-of-the-month-moles-and-voles/
Parkhurst, Jim, “Managing Wildlife Damage: Moles,” Virginia Cooperative Extension Publication, https://pubs.ext.vt.edu/420/420-201/420-201.html
“Voles and Moles in the Lawn,” http://greenviewfertilizer.com/articles/voles-moles.
Species: Moles, http://humanwildlife.cmi.vt.