Overview of Damage Prevention and Control Methods
- Pack the soil to destroy burrows
- Reduce soil moisture and food
- Generally not practical. In small, high-value areas, barriers of sheet metal, brick, or wood might restrict moles
- Not effective
- Castor oil-based repellents
- Warfarin gel bait (Kaput®)
- Bromethalin worm bait (Talpirid®)
- Aluminum phosphide
- Charcoal-based smoke cartridges
- Not practical
- Several specific mole traps are available
- Pit traps
Damage Prevention and Control Methods
Many people lack an appreciation of the importance of moles and the difficulty of gaining complete control where habitat is attractive. If excellent habitat is present and nearby populations of moles are large, control will be difficult. Other moles often move into areas that have been vacated recently.
It is important to properly identify the species of animal causing conflicts before attempting to control the damage. Moles and voles often are found in the same location and damage often is confused between them. Methods for control differ for the 2 species.
Change the composition of the soil to a mixture of heavy clay and rocks to create habitat that is inhospitable to moles. Changes in soil also will impact the types of plants that are capable of living there, so most clients will not tolerate this technique or the costs associated with it.
Pack the soil with a roller or reduce soil moisture to reduce the attractiveness of the habitat to moles. Growth of plants will be negatively impacted by packing the soil and reducing moisture.
The use of insecticides often is not effective for reducing damage done by moles. If populations of soil-borne insects are reduced, moles may increase digging in search of food, possibly increasing damage to turf or gardens. A lawn can be free of grubs and still have moles. Moles eat grubs, but also feed on animals such as worms and ants.
For small areas, such as seed beds, install a fence of 24-inch roll sheet metal or hardware cloth. Place the fence at the surface of the ground, bury it to a depth of at least a foot, and bend it to a 90o angle (Figure 6).
No frightening devices have been proven effective for the control of moles, including vibrational, magnetic, electronic, sonic, and pin-wheel devices.
Castor oil and products made with castor oil, such as Sweeny’s Mole and Gopher Repellent®, have shown minor effectiveness in repelling moles. The product containing castor oil must be thoroughly watered into the lawn. Irrigate the area with ½ inch of water before applying the solution, and follow with at least 1 inch of water. Areas that receive extensive irrigation quickly will lose the repellent due to leaching. For best results, spray the entire area to be protected. Moles may burrow under a treatment made on a perimeter. Preliminary studies on granular materials containing castor oil have been less effective than liquid repellents.
Gopher purge (Euphorbia lathyris), also known as “mole plant,” has been promoted as a repellent of moles, but the effectiveness of this plant is questionable. Gopher purge is poisonous to humans and is a weed that may become a problem. It is not recommended as a technique to control moles.
Always carefully follow the label when using toxicants, as the label is the law. Moles primarily feed on insects and earthworms, so grain-based bait is not likely to be eaten by moles and may be pushed to the surface.
Two other bait products, Kaput® and Talpirid®/Tomcat® may be more effective for the control of moles. Kaput® is a gel that is squirted into a run. Talpirid®/Tomcat® is formulated as a synthetic worm replica that contains bromethalin. Both products claim that moles are attracted to the bait as food. Tomcat®is a General Use Pesticide. Follow all instructions on the pesticide label.
Aluminum phosphide and charcoal-based gas cartridges are fumigants that are registered for use against moles in most states. Aluminum phosphide is a Restricted Use Pesticide and requires that a Fumigant Management Plan be created before application. Fumigants have the greatest effect when the materials are placed in burrows that are deep, rather than runways on the surface. Fumigants can control moles in some situations, but several legal restrictions are related to their use. Follow the directions on the label. Fumigants usually are ineffective where soils are porous and dry, or where there are extensive tunnels near the surface that are used for feeding.
The shooting of moles is not practical.
The most successful and practical method of controlling moles is trapping. Several styles of mole traps are on the market. Each type of trap will deliver good results if handled properly.
Some mole traps are set over a depressed portion of a surface tunnel. As a mole moves through the tunnel, it pushes upward on the depressed roof of the tunnel and trips the broad trigger pan of the trap. Brand names of the most common surface traps include Victor® mole trap, Out O’ Sight®, and Nash® (choker loop) mole trap (Figure 7).
The Victor® trap has sharp spikes that impale the mole when the spikes are driven into the ground by a spring. The Out O’ Sight ® trap has scissor-like jaws that close firmly across the runway, 1 pair on either side of the trigger pan. The Nash® trap has a choker loop that tightens around the body of a mole.
To set a trap properly, select a place in the runway on the surface where there is evidence of fresh mole activity and where the burrow runs in a straight line (Figure 8).
Avoid the twisting ridges on the surface and do not place traps on top of mounds. Insert a harpoon trap so that the stabilizer legs straddle the tunnel (Figure 9).
Use your thumbs to depress the tunnel the width of the trigger until the depression is lower than the soil surrounding, it and the trigger rests squarely on the depression.
To set the harpoon trap, raise the spring, set the safety catch, and push the supporting spikes into the ground, one on either side of the runway (Figure 9). Release the safety catch and allow the impaling spikes to be forced down into the ground by the spring, allowing the spikes to penetrate the soil and leave it. Do not tread on or disturb any other portion of the runway. Leave the tips of the tines in the soil to reduce the risk of accidental impalement (Figure 10). Provided more safety by covering the trap with a 5-gallon bucket.
To set a scissor-jawed trap and Nash-style choker trap, dig out a portion of a straight runway on the surface for the length of the trap. Clean out the tunnel in both directions and create a barrier of soil in the middle
Set the trap and secure it with a safety hook. Force the jaws into the ground so that it straddles and is in line with the runway. The trigger pan must touch the soil that is packed between the jaws. In heavy clay soils, cut a path for the jaws by dry-firing the trap, so the jaws can close quickly. Cover the trap with loose soil or grass so the tunnel remains dark. Release the safety hook before leaving the trap. Mark the trap with a surveyor’s flag to prevent people from accidentally hitting it with a mower.
Some mole traps are set inside tunnels of moles. These traps include the Cinch® mole trap, NoMol®, Gophinator® (Figure 11), and the Death-Klutch® gopher trap.
These traps require less skill to use and they can be hidden from public view. They require more time, however, to monitor. Success or failure in the use of the traps largely depends on the skill and diligence of the operator.
Troubleshooting and Tips
If a trap fails to catch a mole after 2 or 3 days, it can mean the mole has changed its habits or the trap was improperly set. Move the trap to a location with fresh damage. If a mole has dug around the trap, it means that the trap obstructed the runway and forced the mole to move around the obstruction. Move the trap to another portion of the tunnel and reset.
Always spring traps before removing them. Wear glasses or goggles to protect your eyes from debris that may be released by the springing trap. When checking a trap that has been sprung, avoid pulling the trap directly out of the ground. Use a trowel to check both jaws and tines for a mole, as the mole may not be securely caught or dead.
Relocation of moles is not practical.
Translocation of moles is not practical.
Use carbon-dioxide to euthanize moles, if necessary.
Check your state regulations regarding disposal of carcasses.
Other Control Methods
Pit-traps can be successful for the control of moles, but the amount of time and energy involved to capture moles with this method makes them impractical.
Several home remedies, such as placing chewing gum, rose thorns, broken glass, used cat litter, gasoline, and ammonia have been proven ineffective and some may be environmentally hazardous.