The Gwinnett County Extension office receives a lot of calls from people saying that something is digging up their yards. Most often the culprits are moles or voles.
What exactly are these small animals and what is the difference between them? Well, moles are insect-eating mammals called insectivores. They're 5 to 6 inches long with powerful, shovel-shaped front feet used to tunnel below ground. The gray, pig-nosed animals have dog-like teeth and are rarely seen above ground, unlike rodents.
Moles pose no harm to people or pets. A mole can consume its own weight in earthworms and insects daily, and has the ability to tunnel up to 15 feet per hour. The tunnels can damage a young plant's root system and are seldom reused by the mole. A large network of the raised tunnels dug by a couple of moles can ruin a lawn's appearance over time.
Voles are rodents resembling a house mouse but with a shorter tail and smaller ears. They are brown to gray with a lighter-colored belly, and 4 to 6 inches long. Large incisor top teeth distinguish this rodent from a mole. Voles feed on roots, bulbs and other parts of vegetation. They damage plant material by chewing on young trees and shrubs, and can strip the bark of the plant at ground level.
The most visible sign of voles is an extensive surface runway system with numerous burrow openings. The 2-inch wide strips meander through the lawn at the surface. These strips usually end at a hole, often going into an abandoned mole hole. Nicely rounded holes in your yard indicate you have both moles and voles.
Moles and voles damage lawns and gardens differently. Mole damage is usually only cosmetic. They plow the soil by tunneling just under the surface in search of grubs. Mole tunnels can make turf look "cracked."
Voles, on the other hand, do feed on ornamental plants. They damage plant material by girdling the trunks of shrubs and damaging the roots by chewing. Voles are active both day and night.
Moles can be difficult to control. Moles are solitary creatures, and only one or two are usually present in the home lawn. One way to get rid of moles is to reduce their food source. Grubs are the easiest of their food sources to control, and they're controlled by applying insecticides to the lawn. The moles tunnel below the soil surface, and their activity can be easily monitored. Step on each tunnel, collapsing them, and moles will repair the tunnels they use.
Their tunnels are the place where they can be best controlled. The best control method is the use of lethal harpoon traps. The traps are placed over main tunnels and set off by mole movement. If this method is not appealing, fall traps may be made using coffee cans. Bury the cans along mole tunnels where the tunnel is just above the rim of the can. Cover the trap with a board and check it often. The moles will fall into the can when excavating the tunnels and can be disposed of humanely.
Different strategies are necessary for controlling voles. Reducing the amount of groundcover by mowing or some other means is the best way to deter voles from inhabiting an area, because they need plenty of groundcover as protection from predatory birds and mammals. Traps may also be used.
Snare traps and snap traps (traditional mouse traps) can be placed in runways and baited with apple slices. A good method is baiting the traps with small amount of peanut butter or bacon for few nights without setting the traps. When the traps are finally set, there is an element of surprise. Baits or poisons are not available for homeowners to use in controlling voles.
Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at 678-377-4010 or timothy.daly@gwinnettcounty .com.