Answer: Moles feed on grubs and earthworms living in your lawn or garden. The damage they do is to plant roots while they are tunneling. Your first consideration should be to control the grub population in your lawn (have you considered beneficial nematodes or milky spore?) and determine how serious a problem the moles are. Some gardeners consider moles beneficial because they are such good insectivores. If you have a major problem with them, your first task in treating moles is to determine which of their runways are active. You can do this be tramping down areas of raised soil that indicate tunneling. The tunnels that are raised a day later are active. Some methods of treatment are flushing with water (best done in the spring), or protecting your garden by burying a fencing of small mesh, tightly woven hardware cloth, or a low cement wall. You could also try trapping - either the live in a pit trap or using a lethal trap. Moles hate the smell of castor oil beans, and Gardener's Supply Catalog has a repellent out with castor oil as an ingredient that I have heard good reviews about. You can reach them at 1-800-863-1700 or visit their website at http://www.gardeners.com
Moles tend to live a solitary existence except during mating time. Even though you think you've gotten rid of your mole population, you may find that males are cruising through your yard in search of females. Wish I had better news for you but mole control is an ongoing project and it would help if your neighbors went on mole patrol, as well.
Best wishes with your garden!
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