The sudden appearance of raised earth and conical mounds across a manicured lawn indicates mole activity. Identifying the specific pathways used by the animal is the first step toward effective management. Targeting the main travel route, often called the runway or highway, is necessary because the majority of tunnels are temporary feeding routes that are quickly abandoned. Locating this frequently used main corridor is the most reliable way to place controls where the mole will repeatedly encounter them.
Understanding Mole Tunnel Systems
Moles construct an intricate network of passages that serve different purposes, categorized into three main types based on depth and use. Shallow subsurface runways are the most visible sign of activity, appearing as raised ridges in the soil just beneath the grass roots. These tunnels are primarily exploratory feeding paths, where the mole searches for earthworms and other invertebrates, and they are often used only once before being abandoned.
The deep main runways, in contrast, are the permanent infrastructure of the mole’s territory, functioning as high-traffic corridors. These tunnels are typically located deeper, often between 6 and 12 inches below the surface, connecting feeding areas with nesting and resting chambers. Because the mole uses these runways multiple times per day, they are the most desirable locations for intervention. The third category includes the deepest chambers, used for nesting and food storage, which are usually not directly targeted for control.
Visual Clues for Tunnel Identification
Identifying the main runway begins with careful observation of the patterns visible on the surface of the yard. Unlike the shallow, meandering, and zigzagging paths of feeding tunnels, a main runway often follows a relatively straight line across the landscape. Look for a continuous ridge that connects two or more areas of heavy activity, such as large, conical molehills.
Main tunnels frequently run parallel to established boundaries, such as driveways, sidewalks, foundation edges, and fence lines. These structures collect moisture, creating an environment favorable for earthworms, the mole’s primary food source. The molehills associated with a deep, main runway are usually larger and more distinct mounds of pushed-up soil, indicating the excavation of deeper earth. Any ridge that consistently reappears or seems to anchor the overall network is a strong candidate for a main runway.
Practical Methods for Confirming Active Tunnels
Once a potential main runway is visually identified, its activity must be confirmed before proceeding with control measures. The most reliable method is the collapsing test, which exploits the mole’s habit of quickly repairing its primary travel routes. To perform this test, firmly flatten a 6- to 12-inch section of the suspected tunnel using the heel of a shoe or a small board.
Mark the location clearly and check the area 12 to 24 hours later. If the mole is actively using that tunnel, it will have pushed up the soil to repair the collapsed section, confirming it as an active main runway. If the section remains flattened after a full day, the tunnel was likely an abandoned feeding route and should be disregarded.
A secondary technique involves probing the soil to determine the tunnel’s depth and presence where a surface ridge is not obvious. Use a slender tool, such as a metal rod or dowel, and gently push it into the ground a couple of inches away from a raised ridge. The main runway will be detected by a sudden lack of resistance when the probe breaks through the tunnel ceiling, typically at a depth of 6 to 12 inches.
This probing method is useful for locating deeper runways that do not create a visible surface ridge, such as those running beneath a sidewalk or dense ground cover. Confirming the repair of a collapsed section or locating a deep, high-traffic passage precisely identifies the main runway. This verification process ensures that subsequent efforts are focused on the mole’s most dependable travel corridor, increasing the likelihood of successful management.