The Carlisle Mosquito Online

Friday, October 22, 1999


Encountering moles in my back yard

This is that time of year, especially on a warm October weekend when the leaves are falling, that you grab a rake from the tool house and start raking the leaves from the lawn into neat little piles that can be carried to the compost heap or hauled off into the woods. This is also the time of year, once the leaves have been removed, that you start to notice the ridges of soil that mar the surface of the lawn. These ridges or surface tunnels are caused by moles, creatures that spend most of their lives underground.

Molesorder Insectivora; family Talpidae; genus Scalopus; species S. aquaticuseastern moledig loose mounds of dirt, either in small piles (molehills) or ridges (runways) in loose, moist, or sandy soil. The mole spends its life underground in a system of tunnels feeding on worms, grubs and other insect larva. As it tunnels, the mole, using its powerful shoulders and huge front paws, forces dirt upward, creating the ridges of soil on the lawn. In the winter, moles are usually in deep underground tunnels below the frost line. A mole may live for three to five years. It spends most of its life within an area that is less than one acre.

This year, because of the heavy rainfall in September and early October, moles are finding plenty to eat just below the surface of the ground. When the earth is drier, they must burrow deeper to find food. The tunnels are especially noticeable in the spring and fall when the weather has been damp.

Homeowner's fairy godmother?

If it weren't for the damage moles cause to lawns, they would be welcomed as the homeowner's fairy godmother. Among the foods that moles devour are cutworms, ants, slugs, bees, wasps, snails and centipedes. Their tunneling helps loosen, moisten, and aerate the soil. They can be economically beneficial to farmers and gardeners.

The presence of moles is tied to an infestation of grubs and the larva of several kinds of beetles. Grubs damage turf by eating the roots of grass plants. Grubs can cut roots so completely that sections of the lawn can be lifted from the soil like a rug. Once the grubs develop into beetles, they attack flowers and vegetables.

Mole control without chemicals

Controlling moles with poison bait or harpoon traps is generally ineffective. The chemicals and traps that one might purchase from a hardware store appear to have little lasting impact on mole populations. Furthermore, these chemicals are highly toxic to pets and kill birds which eat poisoned insects. Poisons and traps will take the lives of some of the moles that invade the yard, but others will be attracted to the same site as long as the property offers a hospitable environment. Moles produce many more young than are needed to sustain their population.

The Humane Society of the United States has come up with what seems like an ingenious way to get rid of the moles in your yardrepelling moles with odors. Moles have an excellent sense of smell and will retreat when their sensitive noses encounter anything in their surface tunnel that emits an obnoxious odor. The trick is to carefully open the raised tunnel every six feet with a small stick. A teaspoon of repellent is then placed inside, and the opening carefully closed. The reason for not damaging the tunnel is that you are trying not only to get the mole out of the tunnel, but condition the animal to stay out of the yard. The hope is that the mole will associate the odor of the repellent with the entire yard and will therefore avoid the site. The Massachusetts Audubon Society suggests using "Bitter Apple" which can be purchased in pet shops or from feed dealers. For another type of repellent try mixing a concoction of one part scented castor oil, 2 parts dishwashing detergent, and 3 parts water. Put the mixture into a gallon of water (less if you want a stronger mixture) then put into a spray bottle and spray into the hole. Planting Caper Spurge (mole plant), daffodils or castor beans is another possibility. (They do not recommend using mothballs. These leach into the soil, get into ground water, and are extremely toxic.)

To be effective, the repellent must be set in a frequently used tunnel. Usually this is a tunnel that runs along a straight line and appears to connect two systems of tunnels in regular use. To determine which tunnels are active, stamp down a short section of each tunnel. For the next several days re-stamp any sections that the mole raises back up. If a tunnel is raised daily, it is an active runway and the repellent should be placed inside it.

Soil vibrators

Another tactic for repelling moles is to stick toy pinwheels in the ground where there are active tunnels. As the breeze turns the pinwheel it creates vibrations in the ground which annoy the mole and prompt it to leave the area. One other suggestion that some homeowners insist works better than a pinwheel is a wind-propelled lawn ornament. One model of ornament features a wooden woodcutter. The wind causes the woodcutter to repeatedly lift his axe and bring it down against the base of the ornament. As the blocks of wood bang together, they create a powerful vibration in the soil which is sure to get the attention of any resident moles.

Fencing and live trapping are not recommended. Experts are not crazy about the idea of relocating animals. A mole has a homing instinct and will travel as far as 1,500 feet back to its homesite. Relocating animals is in many instances inhumane to the animal and has the potential for transporting diseases. Fencing is time-consuming and often unattractive.

Moles are beneficial

Maybe the answer to this problem comes in the words of a scientist from the Mass. Audubon Information Service who wrote, "The main point is that moles are generally beneficial. Tamp the sod down by foot or by roller periodically and thank your lucky stars that you have a little creature around your home to help you with insect control."

Sources used for this article include: Animal Damage Identification Guide for Massachusetts from the Cooperative Extension Service University of Massachusetts; Country Lover's Guide to Wildlife by Kenneth Chambers; Telephone Manual Outline from Massachusetts Audubon's Laughing Brook Wildlife Sanctuary in Hampden; and A Guide to the Humane Control of Moles from the Humane Society of the United States.

1999 The Carlisle Mosquito