Moles are highly efficient burrowing mammals that spend most of their lives underground, creating extensive tunnel systems as they forage for food. Their presence is characterized by unsightly mounds and raised tunnels, which disrupt turf health and create uneven surfaces across the property. Effectively managing a mole problem begins with accurately identifying the pest and then employing a targeted strategy for control.
Identifying Mole Activity and Damage
Correctly identifying the signs left by a mole is the first step in successful removal, as the damage can be confused with that of gophers or voles. A molehill is typically a volcano-shaped mound of fine, loose soil pushed up to the surface, differing from a gopher mound, which is generally horseshoe-shaped with a distinct soil plug. Moles create two types of tunnels: surface runways and deep tunnels.
Surface runways are feeding tunnels just beneath the turf, appearing as raised ridges that feel spongy when stepped on. These shallow runs, often only three to twelve inches deep, are where the mole seeks its daily sustenance and may be used only once or twice. The deep tunnels, which can be several feet underground, are the main travel routes and more permanent parts of the system used for nesting and shelter. To identify active tunnels, flatten a section of a ridge; if the tunnel is repaired within 24 to 48 hours, it is a frequently used path and a prime location for control methods.
Active Removal: Mechanical Trapping
Mechanical trapping is widely considered the most reliable and effective method for removing moles, often yielding a high success rate when executed correctly. The effectiveness depends on placing the trap in an active main runway, not a temporary feeding tunnel, as moles use these deeper routes consistently to patrol their territory. The three most common types of lethal traps are the harpoon, the scissor, and the choker loop trap, all of which are mechanically triggered when the mole pushes against the mechanism.
Harpoon traps use sharp spikes that are driven into the ground, while scissor traps feature scissor-like jaws that snap shut across the runway. Choker loop traps use a wire loop that tightens around the mole’s body as it passes through the tunnel. To set a trap, locate an active main tunnel, remove a small section of the roof, and position the trap directly over the runway. Ensuring the trap is covered to block out light and secured to prevent accidental movement is important for both safety and efficacy.
Non-Lethal Deterrents and Habitat Modification
Non-lethal methods focus on making the environment undesirable for moles, either by repelling them directly or by reducing their food supply. Commercial repellents often contain castor oil, which is thought to make the mole’s primary food source, earthworms and insects, unpalatable. Applying a castor oil-based solution requires thoroughly saturating the soil and tunnels, often requiring a mixture of castor oil, dish soap, and water to help the oil penetrate the ground. These liquid repellents need frequent reapplication, especially after heavy rain or irrigation, to maintain their effect, and their overall efficacy is limited compared to trapping.
Sonic or vibrating devices typically have poor results because moles can easily bypass the localized vibrations by tunneling around them. A more strategic approach involves habitat modification by controlling the mole’s diet, which primarily consists of earthworms, insect larvae, and grubs. Reducing the population of grubs and other subsurface insects using appropriate insecticides can make the yard less appealing as a foraging ground. However, moles still rely heavily on earthworms, which are beneficial for soil health, meaning eliminating all food sources is impractical and often ineffective as a sole control method.
Chemical Control Methods
Chemical control involves using toxic substances to eliminate moles, primarily through poison baits or tunnel fumigants. The most effective poison baits are specially formulated to resemble the mole’s natural diet, such as a synthetic worm replica containing a toxicant like bromethalin. These baits must be carefully placed directly into active tunnels to ensure ingestion by the mole and to reduce the risk to non-target wildlife. Applying these baits requires adherence to all label instructions, as they are pesticides that can pose a danger to pets, children, and other animals if misused.
Tunnel fumigants, such as gas cartridges, are also available for use in mole control, but their effectiveness is often inconsistent. Moles can quickly plug off sections of their burrow to block gas penetration. Fumigants work best in deep, stable tunnels and are generally ineffective in porous, dry soil or in shallow feeding runs where the gas can escape. Certain highly regulated fumigants, like aluminum phosphide, are restricted-use pesticides and require professional application due to safety risks.