Controlling Nuisance Moles
MOLES are small mammals that spend most of their lives in underground burrows. They are similar in appearance and size to shrews and meadow mice and may occupy the same habitat. They are seldom seen by humans; when seen, they are frequently mistaken for mice or shrews. Only one species--the eastern mole--lives in Missouri. The most conspicuous features of the mole are the greatly enlarged paddlelike forefeet and prominent toenails, which enable the mole to literally swim through the soil. The legs are strong, the neck short and the head elongated. Moles lack external ears and their eyes are so small that at first glance they appear to be missing.
A mole's fur is soft and brownish to grayish with silver highlights. When brushed, the fur offers no resistance in either direction; this enables the mole to travel either backward or forward within burrows.
Moles may be found in woodlands, grasslands and lawns. They construct extensive underground passageways--shallow surface tunnels for spring, summer and fall, and deep, permanent tunnels for winter use. Nest cavities are located underground, connecting with the deep tunnels.
Moles have high energy requirements. They actively feed day and night at all times of the year. They feed on insects--mature and larvae--snails, spiders, small vertebrates, earthworms, and occasionally take small amounts of vegetation. Earthworms and white grubs are favorite foods.
Moles prefer loose, sandy loam soils and avoid heavy, dry clay soils. Mole activity in lawns or fields usually shows up as ridges of upheaved soil created where the runways were constructed as the animals moved about foraging for food. Some of these tunnels are used as travel lanes and may be abandoned immediately after being dug. Mounds of soil called molehills may be brought to the surface of the ground as moles dig deep, permanent tunnels and nest cavities.
Moles breed in late winter or spring and have a gestation period of about four to six weeks. Single annual litters of two to five young are born in March, April, or May. Young moles are born naked and helpless, but growth and development is rapid. About four weeks after birth, they leave the nest and fend for themselves.
Moles in the natural environment cause little damage. They are seldom noticed until their tunneling activity becomes apparent in lawns, gardens, golf courses, pastures, or other grass and turf areas.
The upheaved ridges of mole tunnels make lawn mowing difficult. Since the roots are disturbed, grass may turn brown and unsightly. Moles rarely eat flower bulbs, ornamentals, or other vegetative material while tunneling, but plants may be physically disturbed as moles tunnel in search of animal organisms in the soil. Mole activity may indirectly damage vegetation, but their feeding on insects and other soil organisms is beneficial.
Shrews and meadow mice frequently use mole tunnels as runways and travel lanes. Shrews, like moles, are insectivorous and eat little vegetation. Meadow mice eat a wide variety of vegetative matter and may damage plant life. The general similarity in color and appearance of moles, shrews and meadow mice and their tendency to associate in the same habitat and runways make it essential to understand differences in their habits and to know how to identify each species in the event it becomes necessary to control them.
Control
Changing environment. You can prevent moles from becoming established or can control them once they start digging tunnels by reducing their insect food supply. While this method may take time to become effective, its benefits will persist as long as the animal organisms on which moles feed are kept at a low level. (Note: Such treatment will likely kill earthworms and may discourage bird life.) When used according to the directions on the label, chemical soil treatment to control grubs and other soil insects can provide a safe and satisfactory solution to mole damage. Check with county extension offices for current soil insect treatment.
Trapping. Moles can be captured by using specially designed traps. Harpoon and choker type traps are available through farm- and garden-supply stores or hardware stores. Directions for using these special traps are furnished by the manufacturers.
The selection of actively used runways is important for successful trapping. To determine active runways, press down short sections of the raised ridges and mark these locations. Active runways will be repaired as moles continue to feed and travel, while abandoned tunnels will not be repaired.
Select a fairly straight two- or three-foot section of one of these major runs that has been repaired. Stomp down the middle with your heel to create an obstruction in the tunnel. The trap should be placed over this obstruction so that the mole will spring the trap as it repairs the tunnel. Set your trap according to the instructions included with it, and carefully trigger it a couple of times to see if it is working properly.
A good test to check whether you have a good trap location is to punch a small hole in the run on both sides of the trap with a stick. Moles do not like light and will plug the holes. Later, if the trap is not tripped but the holes are plugged, the animal has passed by but missed the trap. In that case, strike the burrow two or three times with your heel to collapse the new tunnel, and reset the trap. If the trap is not sprung and the holes are not plugged after two days, you probably should move the trap to another location.
When temperatures are cold or hot, moles spend most of their time in the deeper burrows. Therefore, you are more likely to be successful at trapping moles in the spring or fall.
Mechanical. Small areas such as flower beds can be protected by barriers of sheet metal buried in the ground to a depth of at least 12 inches, so as to prevent burrowing.
Pesticides. A number of chemicals are registered and available for use in mole control. However, they are not always effective. Fumigating gases leak from the surface burrows, and toxic baits may not be eaten because of the moles' preference for eating insects and other soil organisms. For these reasons, pesticides are seldom suggested to control moles.
Missouri Department of Conservation, University of Missouri, U.S. Fish & Wildlife Service
