Controlling Moles: Nature’s Tunnelers
As homeowners, many of us have experienced walking outside in the morning and noticing the ridges of pushed up dirt across our yard. Moles, those little tunneling, lawn-damaging critters have struck again.
Moles are small, fur covered mammals that spend most of their lives underground. Even though they may look like a mouse or rat, they are actually insectivores and are more closely related to shrews and bats. A moles’ diet consists of worms, grubs and insects. Their front legs and feet are adapted for digging. They have short, strong feet with wide outward facing palms and large claws. These shovel-like feet allow a mole to dig by using a swimming motion through the soil. Moles prefer sandy loam or loose moist soils over hard, dry, compacted clay. Easy digging usually means better mole habitat.
Moles live underground and spend much of their time tunneling, looking for something to eat. Since moist, fertile soils with lots of organic matter have more earthworms and grubs than dry, hard soils, moles like to tunnel where the food is most abundant. Often this search for food involves forested areas, old orchards, lawns, golf courses, flower beds, gardens and even fishing worm beds. And therein lies the rub with humans because we also like our lawns and gardens.
Controlling moles, like controlling most wildlife species, is a double-edged sword. The digging activity of moles is beneficial to soil mixing and aeration. Additionally, moles consume many destructive insects that damage grasses and garden growth. Since moles eat worms, grubs and insects, most of the damage to plant root systems is caused by mice or other critters using mole tunnels as underground travel lanes. But the tunneling does create unsightly ridges and can cause the grass directly above the tunnel to be less drought tolerant.
With a little effort and persistence, homeowners can control moles. Moles have poor eyesight and hearing. They find food by touch of the hairs on their nose, feet, and head. Control methods such as sonic or vibration devices, chemical repellants and poisons have not proven effective. Moles are insectivores and do not recognize grain or pellets of food.
Fumigants and gas cartridges federally registered for mole control have proven effective when used in the deeper tunnels. The products must be used according to label instructions. Check with your Extension agent or USDA-Animal Plant Health Inspection Service-Animal Damage Control office for information on the safe use and availability of these pesticides.
Barriers can be effective for small areas such as flower, seed or worm beds. A perimeter barrier of 24-inch-wide sheet metal or hardware cloth buried so the material forms an L in the bottom of a trench around the bed is effective. The material should extend 12 inches below the soil surface and outward for 12 inches at the bottom of the trench. Backfill with soil and make sure all joints are tight.
The most effective control method is trapping. Moles dig two types of tunnels or runways. Feeding tunnels are shallow, just below the surface and the deeper travel tunnels are usually 2 inches to 2 feet deep. The zigzagging feeding tunnels are seldom used on a regular basis while the deeper, straighter tunnels are used regularly. This usage habit is the key to stopping moles. Trap placement is determined by these usage patterns.
Several different mole traps are available but they all must be set over a flattened portion of a surface tunnel. The trap trigger is tripped when the mole reopens the closed tunnel and pushes the flat tripper plate up. Several companies make traps but the three types most often used are spike or harpoon traps, loop or choker traps, and scissor jaw traps. The spike trap releases sharp spikes straight down and impales the mole, the choker trap catches the body of the mole in a loop or lasso of wire when triggered, and the scissor jaw trap catches the males between metal fingers that close from either side of the tunnel. All are effective but the harpoon probably is the easiest to set up.
To find which runways are being used, step on the humped up tunnels in several spots around your yard. Check to see if the flattened portion is pushed back up within the next day or so. If it is, you have a trap site. If you don’t catch anything in two to three days, try another site. Traps can be dangerous. Read the instructions carefully and use only if you feel qualified.
Moles fulfill many useful functions in the environment. Remember, even if you are successful removing the offending individual, another may return if the food and right conditions persist. If you can co-exist with moles, you both may be better off.
By Gene Carver, Wildlife Biologist, Division of Wildlife and Freshwater Fisheries
Reprinted with Permission
