The mole is a small, specialized mammal, belonging to the order Eulipotyphla, making it an insectivore rather than a rodent. Moles lead a life almost entirely beneath the surface of the soil, a habitat they shape themselves. Their existence is defined by their ability to dig, and their underground world consists of an elaborate, functional network of tunnels. The continuous excavation of this subterranean environment is the central activity that allows them to survive and forage.
Physical Adaptations for Digging
The mole’s body is optimized for constant excavation. Their forelimbs are their primary digging tools, rotated outward from the body. These powerful limbs end in broad, paddle-like paws equipped with robust, spadelike claws that shovel soil efficiently. The shoulder girdle and associated musculature are significantly enlarged, providing the force necessary to push through compacted earth.
This powerful upper body allows the mole to use a fore-and-aft motion, similar to a breaststroke, to shear and displace the soil. Their eyes are extremely small, often hidden beneath their fur, as vision is unnecessary in the darkness of their tunnels. Furthermore, the mole’s dense, velvety fur can lie flat in any direction, preventing resistance and allowing them to move forward or backward through narrow passages.
The Design and Purpose of Mole Tunnels
Mole tunnels are a highly organized, territorial network that serves as a permanent hunting and living structure. The tunnels are categorized into different types based on their depth and function. Shallow surface runs are temporary passages created just beneath the topsoil, often visible as raised ridges. A mole rapidly extends these tunnels while foraging for earthworms and insect larvae, digging up to 100 feet in a single day as they follow their prey.
The more established routes are permanent runways, which are deeper, firm-walled thoroughfares used for patrolling the territory. These routes can descend to depths of 70 centimeters (about 28 inches) and are patrolled multiple times daily. They act as a giant, underground trap to collect passing invertebrates. A single mole maintains this extensive network, which can stretch for over 70 meters.
Central Living Chambers
Central living chambers are excavated at the greatest depths, sometimes three feet or more underground. These deep structures are reserved for nesting, resting, and raising their young. The location of these chambers, often under a tree root or paved area, provides stability and protection from predators and temperature extremes. This structured environment provides shelter and a consistent food source.
Understanding Molehills and Excavated Soil
The most visible evidence of a mole’s underground activity is the molehill, the familiar conical mound of loose soil. These mounds are the result of the mole excavating its deep, permanent tunnel system and living chambers. As the mole digs into the compacted soil, it must dispose of the spoil material.
The mole pushes this excavated earth up vertical tunnels to the surface, creating the characteristic pile. Molehills indicate the construction, repair, or maintenance of the deeper routes, rather than the creation of the shallow surface runs. The frequency of new molehills signifies a period of construction, such as when establishing a new territory or deepening existing structures in response to seasonal changes.