EC 987 • Reprinted March 2002 $1.00 ontrolling Moles

L.W. Kuhn and W.D. Edge

Moles belong to the Cascades in Oregon and procedures for controlling the Cmammalian order Insectivora, Washington and is found in a three larger moles. the insect eaters. Often, small area in southern British Though differing slightly however, they are lumped Columbia and in northwestern in size, color, and distribu- incorrectly with the rodents, California. tion, Townsend’s, broad- which include mice, rats, The broad-footed mole, footed, and Coast moles have squirrels, and other gnawing Scapanus latimanus, is some- much in common. All have mammals in the order Roden- what smaller than Townsend’s rounded or cylindrical bodies tia. Moles are found through- mole and is more silver-gray with pointed, somewhat pig- out the eastern half of the or copper-brown in color. It is like snouts and short, bare or United States and along the found from the Klamath Basin sparsely haired tails. Front Pacific Coast. Four species of of south-central Oregon south- feet are broad, with out- moles are found in the Pacific ward throughout much of wardly turned palms, and are Coast states. Three of these California, except in the drier armed with strong nails. Eyes belong to a single genus, desert regions. are tiny and well concealed in Scapanus. The Coast mole, Scapanus the short, dark, velvetlike fur. Townsend’s mole, orarius, is about half as large There are no external ears. Scapanus townsendii, black to as Townsend’s mole and Moles use their sensitive brownish black in color and occupies much of the same snout, tail, and perhaps approximately 6 to 9 inches area. It is found farther east in sensory hairs as an “early long, is the largest and causes Washington and Oregon and warning system” to detect the greatest damage to lawns, northward into southern enemies and to locate food. gardens, and croplands. This British Columbia. mole is common in the moist, The fourth mole, fertile soils west of the Neurotrichus gibbsii, or “shrew-mole,” is blackish in Lee W. Kuhn, professor color and about the size of a emeritus of wildlife ecology, common house mouse. It and W. Daniel Edge, Extension closely resembles a shrew in wildlife specialist, Oregon appearance and habits. Present State University. throughout the coastal low- lands from California to British Columbia, it is not abundant nor is it a problem for the home gardener, orchardist, or farmer. As an insect feeder, it probably is beneficial rather than harmful and is not included in this review of methods and an ecological role by aerating Mole mounds the soil and mixing surface and burrow systems and subsurface soil layers. I Cover pasture Mole damage Moles sometimes eat or grasses and damage tulips, lilies, iris, legumes, reducing carrots, potatoes, peas, beans, production corn, oats, wheat, and many other plants. Individual moles I Make harvesting might feed heavily on such difficult by plug- items. Up to 20 percent of the ging or breaking diet of Townsend’s mole is plant material. harvesting equip- Some losses are caused by ment the mole’s eating habits, but I the primary damage results Contaminate hay from burrowing and mound- and silage with dirt, building activities. Moles rarely are seen which retards Figure 1.—Mole mounds tend to be circular with a plug in the proper curing unless captured in traps or middle. Compare with the pocket gopher mound in Figure 2. killed while burrowing near I Make ideal seed- the surface. But mounds of beds for undesirable loose soil pushed to the 30 inches or more. Moles are baits and well-set traps surface indicate their pres- grasses and weeds active throughout the year and usually controls them. ence. Moles continually make regular use of the tunnels Urban dwellers are I excavate new tunnel systems from 6 to 10 inches deep. frustrated by this pesky little Damage and or extend old ones. They disfigure lawns and During periods of severe cold animal and dirt piles that pop dispose of the excess soil by or extremely dry weather, up overnight in lawns, flowerbeds digging a short lateral tunnel earthworms become scarce in gardens, or flowerbeds. But to the surface and shoving the I the upper soil layers, and usually only one or two Expose shallow- soil out on top of the ground. moles move into the deeper moles are present, and they rooted shrubs and The resulting mounds, though tunnels in search of food. At are eliminated easily. plants to drying and superficially resembling those such times, surface burrowing of pocket gophers, usually are to insect pests and mound-building activities Recommended more rounded and symmetri- are minimal, and control cal. The mounds are built up, controls measures might be less You can control moles volcano fashion, by repeated effective. effectively by the proper use “eruptions” of soil pushed up A single litter is born in The number of mounds or of poisoned baits or traps or a through the center of the pile March or April, averaging ridges in any given area does combination of both meth- (Figure 1). Pocket gophers three or four naked young. not indicate the number of ods. Use traps for moles in usually push soil out to one Young moles mature quickly moles present. A single home gardens, lawns, or side, resulting in a flattened and are fully furred, nearly Townsend’s mole might flowerbeds, as generally only semicircle or fan-shaped adult size, and on their own in construct from 50 to 100 a few moles are involved. mound, the plugged exit hole about a month. Average life mounds in a month. In coastal For larger areas such as at one side of the pile span is about 3 years. Moles dairy pastures of Tillamook fields, pastures, and golf (Figure 2). Thus, although do not hibernate, but are County, Oregon, densities vary courses, properly placed similar, the workings of these active throughout the year. from one mole in 6 acres to toxic baits usually are more two small earth movers are Surface activity slows during more than five per acre, but effective and less time noticeably different, an periods of extreme cold or average only about two per consuming. Baiting might important distinction in proper drought. acre. Some of these pastures prove to be the simpler and control of both pests. Moles generally are appear to have been “plowed” quicker method, but traps The burrow system is beneficial because of the by the moles, yet the mounds probably will be necessary as a vast network of intercon- number of insects, insect are caused not by hundreds of a follow-up to eliminate necting tunnels and passages, larvae, and other invertebrate moles but by a few. Persistent animals that avoid the baits. prey they eat. They also play varying in depth from 3 to and careful use of poisoned Trapping contrast, when trapping pocket In the Pacific Northwest gophers, leave the burrow the scissor-jaw (tunnel trap) system open with the trap in mole trap is recommended place. The gopher springs the (Figure 3). By using a probe trap when it replugs the open or iron rod, locate one of the tunnel with soil.) mole’s main underground The “harpoon” or “spear” tunnels (Figure 4). Usually type trap (Victor mole trap), these are 6 to 10 inches commonly used in the eastern beneath the surface. Probe states, is not recommended for between two fresh dirt catching western moles. It will mounds, or a foot or more work, however, if set on a dirt from a single mound, to plug in the deeper tunnels as ensure finding a main tunnel illustrated for the scissor-jaw and not a side tunnel. Using a trap. garden trowel or small shovel, remove a section of Toxic baits sod and soil slightly larger Because of constantly than the trap width (about changing labels, laws, and Figure 2.—Typical pocket gopher mound, in cross-section and 6 inches). The success of this regulations, Oregon State from above. The pocket gopher pushes soil out (top), creating a trap depends on building a University can assume no fan-shaped mound (above). The gopher then closes the hole with a soil plug. Compare with the mole mound in Figure 1. firm plug of soil in the center liability for the consequences of of the opened runway for the use of chemicals suggested Figure 3.—The trigger pan to rest on. here. Read and follow the scissor-jaw Moist soil from the opened directions and precautionary (tunnel trap) tunnel or from a nearby fresh statements on the specific mole trap on mound can be pinched pesticide product label. the left is recommended together to build the plug. Because moles are insecti- in the Pacific The set trap (with safety catch vores, eating mainly earth- Northwest. The in place) is then wedged worms and insects, toxic baits “harpoon” or firmly into the opened burrow are not readily eaten. Zinc “spear” type with the trigger snugly phosphide is a general-use trap (Victor mole trap) on against the top of the dirt pesticide registered in Oregon the right is not plug. Take care when placing for control of moles. recommended the trap so that the open trap Proper baiting placement is for western jaws straddle, but do not the key to success. As when moles. protrude into, the open ends trapping, locate a main runway of the mole’s tunnel. A with a probe or iron rod. Rotate carelessly set trap often will the probe gently to enlarge the cause the suspicious mole to hole and drop a teaspoon of bait back up and burrow around or into the hole so it falls to the under it. floor of the underground tunnel Sift loose dirt onto the set (Figure 4). Close the hole with Other control its way to extend tunnels into trap to about the level of the a clod or by gently pressing measures new areas. coil spring. This excludes with the heel of your shoe so light from the opened burrow loose dirt does not filter Poison gases Flooding and fumigants and makes the mole less through to cover the bait. Three Poison gases, some Flooding the burrow suspicious of the plugged or four bait placements in the marketed as “gas bombs,” system with a garden hose tunnel. Release the safety area of freshest mounds are are effective for mole rarely is effective. Unless you catch, and the trap set is enough. Don’t expect instant control. However, gases are can flood the entire burrow complete. success. If additional new not recommended for system quickly and com- When digging through the mounds appear after several controlling moles in pletely, which seldom is plug to reopen its blocked days, rebait. Remember, the extensive tunnel systems; possible, you might only burrow, the mole springs the mole must find the bait in its the mole usually can plug stimulate the mole to tunnel in trap and is caught. (By maze of underground tunnels, and seal off the gassed other parts of your yard. then feed on it. section quickly and go on detected in a newly formed then continuous, persistent mound, a well-aimed blast application of effective from close range does the rest. methods and materials. Mole The mole either is killed traps and recommended directly by the shot discharge poisoned bait, properly or indirectly by concussion. A placed, are the two most hard blow with a long-handled effective methods for shovel, directed at the moving controlling moles. dirt pile, sometimes will Once you have controlled accomplish the same end. damage you will want to (b) monitor the area for rein- (a) Gimmicks and gadgets festation. Reinfestation is Figure 4.—(a) To bait, probe to locate a main runway, enlarge Nearly everyone has heard recognized easily because of the hole by rotating the probe, remove the probe, drop bait of a sure-fire remedy for mounds and surface runways. through the probe hole, and close the hole to exclude light. controlling pest animals, Initiate appropriate control (b) The proper way to set a scissor-jaw mole trap is shown. Note especially moles. These methods as soon as mounds the trigger pan is resting firmly on a plug of dirt in the center. Sift include broken bottles, ground or surface runways appear. loose soil around the trap jaws to the level of the spring, or cover with a bucket, board, or tar paper to exclude light. glass, razor blades, thorny rose branches, bleaches, various Insecticides or soil petroleum products, mothballs, Legal status fumigants used to eliminate sheep dip, common household earthworms and soil-dwelling lye, and even human hair Use pesticides I Moles are classified insects might cause moles to placed in the burrow. Other ! safely move to nearby areas where devices include mole wheels, I as nongame wildlife this food source is more windmills, whistling bottles, Wear protective clothing under the Oregon plentiful. A partial removal of and electromagnetic devices and safety devices as wildlife codes and earthworms might only cause designed to frighten moles recommended on the are not specifically moles to increase their from an area. label. Bathe or shower after each use. protected. tunneling and burrowing in Another supposed cure-all search of food. Generally, is the so-called “mole plant” or I Read the pesticide label— this is more expensive than caper spurge, Euphorbia I The wildlife codes even if you’ve used the poisoning or trapping. lathyris. When planted permit a landowner pesticide before. Follow frequently throughout lawns closely the instructions on or agent to control Shooting and flowerbeds, such plants the label (and any other noxious animals on Some farmers have found serve as living repellents. directions you have). his or her property. the 12-gauge shotgun an However, none of these effective tool in rural areas approaches has proven to be I Be cautious when you I Moles in Oregon where this method can be effective in controlled scien- apply pesticides. Know are not protected applied safely and legally. tific studies. your legal responsibility as Drag the fields or pastures to under federal Unfortunately, there are no a pesticide applicator. You flatten all old mounds, then shortcuts when controlling regulations. may be liable for injury or simply patrol until a fresh moles. Just as in the control of damage resulting from push-up shows a mole other pests, success involves pesticide use. repairing the damaged burrow knowing something about the system. When movement is animal and its living habits,

Illustrations of mole and pocket gopher tunnels and mounds reproduced with permission from Wildlife Pest Control, Publication 21385, Cooperative Extension, University of California.

© 2000 Oregon State University. Produced and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Extension work is a cooperative program of Oregon State University, the U.S. Department of Agriculture, and Oregon counties. Oregon State University Extension Service offers educational programs, activities, and materials—without discrimination based on race, color, religion, sex, sexual orientation, national origin, age, marital status, disability, and disabled veteran or Vietnam-era veteran status. Oregon State University Extension Service is an Equal Opportunity Employer. Revised June 2000. Reprinted March 2002.