OSU pub offers info on mole control

Last Updated: 
August 4, 2008

CORVALLIS - Do you have soft volcanoes of dirt in your yard? Chances are, you may have moles, creatures adapted totally to life underground.

Moles are insectivores, not rodents, explained Dan Edge, wildlife specialist with the Oregon State University Extension Service. They have rounded or cylindrical bodies, somewhat pig like snouts and short, bare or sparsely haired tails.

With outwardly turned palms and strong nails, moles are equipped for efficient digging. Their tiny eyes are well concealed in short, dark, velvety fur. They have no external ears.

Oregon has four species of moles: Townsend's, broad-footed, coast, and the shrew mole. All dine primarily on insects and their relatives, rounded out with an occasional botanical treat, including plants and bulbs from the home garden.

Moles are rarely seen above ground. It is their mounds of loose soil pushed to the surface that indicate their presence. Active throughout the year, they continually excavate new tunnel systems or extend old ones. Because they aerate and mix the soil and feed on insects, insect larvae and other invertebrates including earthworms, moles play a beneficial role in the environment.

But home gardeners and farmers find moles to often be a major nuisance because of their mounds and their vegetarian snacks. Mole mounds make ideal seed beds for undesirable grasses and weeds. And they can expose shallow-rooted shrubs to drying and insect pests.

Moles will sometimes eat or damage tulips, lilies, iris, carrots, potatoes, peas, beans, corn, oats, wheat and many other plants.

Many home gardeners are confused about how to tell the difference between mole and gopher mounds. And being able to identify the critters is the most important first step in controlling them.

Mole mounds are rounded and symmetrical.

"Moles dispose excess soil by digging a short lateral tunnel to the surface and shoving the soil out on top of the ground," said Edge. "The mounds are built up, volcano fashion, by repeated 'eruptions' of soil pushed up through the center of the pile. "Pocket gophers, on the other hand, push soil out to the side, resulting in a flattened semi-circle or fan-shaped mound, with their plugged exit hole at one side of the pile," he said.

Get more information on Controlling Moles (PDF), EC 987.

Author: Carol Savonen
Source: Dan Edge