Ground moles are small, subterranean mammals belonging to the family Talpidae. They are primarily known for the distinctive ridges and mounds they create while excavating their tunnel systems. Their specialized anatomy allows them to spend nearly their entire lives underground, providing characteristics necessary for accurate identification.
Overall Body Shape and Size
The ground mole possesses a compact, cylindrical body shape, which minimizes friction and allows for fluid movement through the soil. An adult mole typically measures between five and seven and a half inches in total length, including its small tail. Most common species, such as the Eastern mole, weigh between 2.5 and 5 ounces.
The head is set directly onto the body, giving the appearance of no neck, which provides a rigid structure to support powerful digging muscles. Its coat consists of short, dense, velvety fur, typically brown, dark gray, or taupe. This unique structure allows the mole to move both forward and backward through tunnels without the fur catching on the walls. The tail is short and stubby, often sparsely covered with hair, functioning primarily as a tactile organ for balance and navigating underground.
Specialized Forelimbs and Claws
The mole’s forelimbs are its most defining characteristic, designed to function as powerful shovels. These limbs are short and robust, rotated outward from the body so the palms face laterally and slightly backward, creating a permanent, sprawling posture. This orientation allows the mole to execute a powerful, breaststroke-like digging motion that efficiently displaces earth.
The hands (manus) are oversized and broad, significantly wider than the mole’s head, appearing as flat paddles. The strength for digging comes from a unique skeletal structure, including a massive, wide humerus bone that provides a large surface area for the attachment of powerful chest and shoulder muscles. The manus is further broadened by the falciform bone, which acts like an additional digit to increase the digging surface area. Each digit is tipped with a long, thick claw, allowing the mole to generate impressive leverage and force to carve tunnels through compact soil.
Head, Snout, and Sensory Adaptations
The head is dominated by the highly specialized snout, which acts as the primary sensory tool. The snout is long, pointed, and extremely flexible, extending beyond the mouth. Most species possess thousands of microscopic sensory structures called Eimer’s organs, which cover the hairless tip of the snout.
These complex Eimer’s organs are densely innervated epidermal papillae that function as sophisticated mechanoreceptors, detecting subtle changes in pressure and texture. By repeatedly touching the snout to the ground, the mole can rapidly detect and discriminate small objects, using touch to locate prey such as earthworms. The mole’s eyes are minuscule, often covered by fur or skin, and provide little functional vision. External ear structures are absent, with the ear canal opening concealed beneath the dense fur. The mole relies almost entirely on its acute sense of touch and smell, utilizing the specialized Eimer’s organs, to navigate and hunt beneath the surface.