Soil mounds are appearing all over my yard, ruining my lawn, my flower beds, and my vegetable garden. It's a mole invasion.
Although I thought moles were rodents, they are actually insectivores, related to shrews and bats. They do not eat plants, as do voles, also known as meadow mice. However, they may damage plants' roots as they tunnel underground.
As they tunnel, they leave volcano-shaped hills of soil above ground. They are active throughout the year and do not hibernate. These little pests have no external ears and very small eyes. Their broad front feet are webbed so that they can "swim" through the soil, chasing insects for dinner. They are about 7 inches long and weigh 3 to 4 ounces.
Moles generally live alone underground, only accidentally coming to the surface now and then. Their tunnels may be used only once, or as regular highways. Voles and house mice may also use mole tunnels. Moles make their homes in dry spots, but hunt in cool moist soil, such as my lawn, where they can find worms, insects, and grubs.
Because they spend their lives underground, moles have few natural enemies. Dogs or coyotes may dig up a few, and an occasional cat or hawk may pry one out of the ground. However, floods are their worst enemy.
Exclusion is not a practical method of controlling moles, except in small areas. Barriers must be placed above ground and underground, and be made of hard, durable materials, such as sheet metal, brick or wood.
Packing the soil destroys burrows, and sometimes the moles, if done early in the morning or late evening. Reducing soil moisture can help to discourage moles from hanging around. There are no registered repellents for mole control, and since moles don't eat grain, toxic baits are ineffective.
Trapping is one effective way to control moles. Scissor-jawed traps, harpoon traps, and choker traps are available. Traps must be properly set. Excavate the mole tunnel, and then replace the soil, packing it firmly where the trigger part of the trap will rest.
Moles can be caught alive, but that takes time, patience, a container such as a three-pound coffee can, and a board. And, what does one do with a live mole? I have a good description of this and other trapping techniques that I can share from "Prevention and Control of Wildlife Damage" by University of Nebraska, if anyone is interested.
The final alternative in dealing with moles is to simply try to appreciate them, adopting the "live and let live" philosophy. Seeing the glass half-full, moles aerate the soil and move the humus around, feeding deeper levels. And, they keep insect populations under control.
For information, e-mail skellyj@unce.unr.edu or call me at 887-2252. You can "Ask a Master Gardener" by e-mailing mastergardeners@unce.unr.edu or call your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu.
• JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension.