Have you ever gone out to work in your garden and found your prized produce plagued by bites too large to be from any insect? Do you have so many holes in your yard you could use it as a golf course? Have innumerable little burrowing animals chiseled away at the trees in your orchard? If any of these questions hit a little too close to home, then you might have a problem with vertebrate burrowing animals. These pests can leave dirt mounds and holes in your yard and wreak havoc on vegetation. Their destructive habits can leave you wondering how to get rid of moles or squirrels or gophers—and how to keep these animals out of your garden. But before you start blasting holes in your yard, Caddyshack-style, make sure you know what kind of critter you’re dealing with.
Often mistaken for mice, voles are small rodents with smaller ears and shorter tails than their doppelgangers. They have dark brown fur and can grow to 7 inches long. The three distinct species of vole are the prairie vole, the meadow vole and the pine vole. Each lives in the range that you would expect: Prairie vole habitats cover the Great Plains; meadow voles range in most eastern states and the Midwest; and pine voles live primarily in the forests of western states.
Damage from prairie and meadow voles is very similar — both leave “runways” that look like little trenches throughout an open area. The burrowing animals usually cover these runways with loose vegetation, such as mulch, grass clippings or leaves, and at the end of the runways they build burrow holes where they breed and nest. All species have a propensity for gnawing at the roots and bases of fruit trees. This “girdling” effect is very pronounced, as they chew away at the darker outer bark to reveal the lighter, more tender bark underneath. “Stalky” and low-fruiting garden plants, such as cauliflower, artichokes and Brussels sprouts, as well as root vegetables, such as beets and carrots, are especially at risk for vole damage.
Pocket gophers live in nearly every state west of the Mississippi River and resemble a cross between a rat and a mole. Their fur color can range from light brown to nearly black, and they sport short tails and large, wide front feet for digging tunnels and dirt mounds. The pocket gopher gets its name from the large cheek pouches it keeps tucked behind its sharp, chisel-like front teeth. These front teeth always protrude from its mouth and grow quickly, so the gopher needs constantly chew to keep its teeth at a manageable size. This habit makes pocket gophers one of the most frustrating burrowing animals to deal with. Not only do they eat and damage the roots of various crops and plants, but also they can easily chew through irrigation lines and power cables. Most of the time a gopher will eat vegetation it comes across while digging, and occasionally it will venture out of its mound to snag something to eat— but by no more than a body’s length.
Photo by iStock/Susanne Friedrich
Other than damage to vegetation and utility lines, the most visible signs of gophers are the distinct dirt mounds they make. These crescent-shaped mounds are often mistaken for molehills, but these dirt mounds have a unique shape. Gopher mounds are shaped like a “C,” with a plug of soil in the center that acts as a door for gophers, whereas molehills are a solid cone of earth with no distinct shape or plug. Gophers also tend to stay deep enough underground that they make no raised tunnels as moles do.
The term “ground squirrel” refers to no specific animal; it is an umbrella term for many different kinds of rodents, including chipmunks and marmots. The three most common in the United States are the eastern chipmunk, the thirteen-lined ground squirrel and Franklin’s ground squirrel. Ground squirrels live in nearly every region in the United States and can grow up to 14 inches long, depending on the species. Smaller varieties resemble common tree squirrels but have shorter tails, smaller ears and distinct coloration, again depending on species. The eastern chipmunk sports two “racing stripes” along its back, while the thirteen-lined ground squirrel has many thin stripes separated by rows of small spots. Franklin’s ground squirrel has no distinct markings but has a solid-color fur that can range from brown to silver.
Photo by iStock/digi_guru
Ground squirrels cause damage in many ways. While they tend to forage for food aboveground, they dig numerous burrows to use as shelter between meals. Ground squirrels feed on grasses, grains, and newly-sprouted plants and produce, and they also have been known to dig up freshly planted seeds and bulbs, and to gnaw on sprinkler heads, irrigation lines and garden hoses. On rare occasions, ground squirrels also have been carriers of bubonic plague. While there are, on average, only seven cases of bubonic plague per year, you should still take precautions when handling these animals. Also note that in some states, Franklin’s ground squirrel has protected status, so check with your local wildlife bureau.
Also known as a woodchuck or whistle pig, a groundhog is a large variety of ground squirrel of the marmot genus. Physically, groundhogs range in coloration, from brownish-gray to black and have stout, stocky bodies that can grow to be more than 16 inches long, and weigh as much as ten pounds. Groundhogs mainly range in the portion of the United States east of the Missouri River but also live in the eastern regions of the “tornado alley” states, such as Kansas and Oklahoma. They prefer open rangeland in which they build their system burrows but can also be found in wooded or “shrubby” landscapes. These burrow systems can have anywhere from two to three openings, each 10 to 12 inches in diameter, with the main entrance marked by a dirt mound. Secondary entrances are hard to locate, as they usually have no dirt mounds.
These secondary entrances can be a safety hazard to both humans and large animals because they’re usually hidden to protect the burrow from predators. In addition to the physical damage that comes from these burrowing animals, groundhogs can be the culprits behind destruction to vegetation and utility lines. They feed on alfalfa, clover and other grasses but also eat soybeans, peas, carrot tops and Fabaceae. They primarily feed in the evening and early morning and will not usually venture out of their burrows more than 50 feet. Groundhogs can be very active during the day and can often be seen dozing on fence posts or low tree branches.
Moles often get a bad rap as yard and garden pests, but they can actually be very beneficial to an ecosystem at large. The tunnels and dirt mounds that these critters create can be an eyesore, but they also help aerate the soil and provide channels for excess water. Moles’ droppings keep things fertile. Moles reside in nearly every region in the United States except the Southwest. They aren’t rodents but are a type of burrowing mammal known as a talpid. All breeds of mole are similar in appearance—they have velvety fur, large front paws for digging, and no noticeable eyes or ears. Depending on the species, moles can grow up to 8 inches long.
Damage from pocket gophers is often blamed on moles and vice versa, but their burrowing and feeding habits are very different. Whereas gopher tunnels aren’t visible aboveground, moles leave behind raised tunnels between hills. These are the moles’ feeding tunnels, where they hunt for insects and worms that live in the ground. These tunnels are made on an as-needed basis while the moles hunt and can be easily tamped down with a foot or shovel. Moles do very little damage to vegetation and produce, but they have the potential to push newly planted seedlings out of the soil, so farmers and gardeners still have reason to learn how to get rid of moles naturally. As insectivores, moles don’t eat plants; they often will go around or tunnel under obstructions, such as roots and utility lines, as their teeth aren’t adapted for gnawing like rodents’ teeth are.
How to Get Rid of Burrowing Animals
Although people use chemical solutions to get rid of burrowing animals, many gardeners and home owners have learned how to get rid of moles and other animals naturally. With a little planning and attention, methods of natural mole control—such as habitat modification and barriers—can effectively keep animals out of your garden and keep their mounds of dirt and holes out of your yard.
Make sure your space is clear of food sources and ground cover, such as leaves and grass clippings, to greatly reduce the likelihood of a vole infestation. Cover the base of young trees and plants with a partially buried plastic or wire collar to protect them from girdling animals.
Trapping is another effective method of controlling burrowing animals. You can trap voles with simple mousetraps positioned in their runs near the burrows, whereas you’ll need larger, specialized traps to effectively capture gophers, ground squirrels and moles.
To keep burrowing animals out of your garden, construct an L-shaped barrier of 1/4-inch hardware cloth around the area you want to keep pest-free. To do this, bend a few inches of hardware cloth at a 90 degree angle, and then bury it below ground. Make sure you have enough cloth aboveground to protect your garden (specific dimensions for hardware cloth barriers are listed below). This barrier should be built 2 feet from any plant beds to protect developing roots from damage. You can also use hardware cloth to completely line the bottom of raised garden beds to keep the animals out of your garden.
Diagram courtesy the Washington Department of Fish and Wildlife
When dealing with voles, bury your hardware cloth 6 to 10 inches below the ground with a raised section of at least 12 inches. The foot of your “L” should be 1 to 2 inches.
Photo by iStock/CreativeNature_nl
To keep gophers out of your garden beds, bury your hardware cloth at least 2 feet deep, with 6 inches of cloth forming the foot of the “L.” Ensure that at least 12 inches of cloth remain aboveground to prevent surface assaults.
For ground squirrels, bury your hardware cloth 6 inches below ground, with 1 to 2 inches of cloth forming the foot of the “L.” Make sure the cloth extends 18 inches aboveground.
Bury your hardware cloth at least 12 inches below ground, with 2 extra inches forming the foot of your “L.” There also should be 3 feet of fencing aboveground.
Photo by iStock/jimkruger
Bury your hardware cloth 2 feet below ground, with 6 inches of bent cloth forming your “L” foot. There also should be 6 inches of cloth sticking up aboveground to deter moles from entering the exclusion area.
Photo by iStock/nwbob
While many chemical deterrents for dealing with critter invasions are on the market, waste from domestic animals can work just as well. Plug holes with waste from cats, dogs and even ferrets to dissuade burrowing animals from surfacing.
Commercial and homemade castor-oil-based repellents have been shown to be somewhat effective for natural mole control. To make a homemade castor oil repellant, combine 1/2 cup of castor oil with 1/2 cup of dishwashing liquid. Mix 2 to 3 tablespoons of this concentrate in a gallon of warm water, and spray the concoction around areas you want to protect from moles.
You can also consider a number of electric deterrents that use ultrasonic sound or vibrations to scare pests off your property, but their effectiveness is debatable.
There’s always the option to let nature take its course when it comes to burrowing animals. Predators, population fluctuations, and migration due to unfavorable habitat conditions can all be helpful in the fight against pests. However, this ultimate natural method can be inefficient and time-consuming and can end up costing you more damage in the meantime.
Sometimes a good dog or cat can help solve your pest problem, or, if you’re a good enough shot, you can get rid of pests with a firearm.
This piece on how to identify and get rid of burrowing animals was adapted from:
University of California Pest Notes Publication 7439 – Voles (Meadow Mice)
University of Nebraska-Lincoln Extension, Institute of Agriculture and Natural Resources – Controlling Vole Damage
Alabama A&M and Auburn Universities – Controlling Voles
University of California Pest Notes Publication 7433 – Pocket Gophers
Utah State University Cooperative Extension – Wildlife Damage Management Series: Pocket Gophers
Oklahoma State University Cooperative Extension – Controlling Pocket Gophers
Colorado State University – Natural Resources Series: Managing Pocket Gophers
University of Illinois Extension – Living With Wildlife in Illinois: Ground Squirrel
Perdue – Wildlife Conflicts Information Website: Ground Squirrels
University of California Pest Notes Publication 7438 – Ground Squirrel
Perdue – Wildlife Conflicts Information Website: Moles
University of California Pest Notes Publication 74115 – Moles
Washington Department of Fish & Wildlife – Living With Wildlife: Moles
Mother Earth News – How Do I Stop Moles from Damaging My Garden
University of Nebraska-Lincoln Extension, Institute of Agriculture and Natural Resources – Woodchucks
Massachusetts Executive Office of Energy and Environmental Affairs – Preventing Damage by Woodchucks
Missouri Department of Conservation – Woodchuck (Groundhog)
University of Missouri Extension – Managing Woodchuck problems in MissouriInternational Union for Conservation of Nature RED list
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