The groundhog, also known as the woodchuck, is a large, stout rodent classified as a member of the squirrel family (Marmota monax) across North America. These terrestrial animals are exceptional diggers that spend a great deal of time underground. Their ability to survive and maintain their complex burrows depends entirely on the robust and specialized tools located in their mouths.
The Groundhog’s Specific Tooth Count
A groundhog possesses a total of 22 teeth, which are divided into two distinct types that serve different functions. The most noticeable are the four large, chisel-shaped incisors, with two situated on the upper jaw and two on the lower jaw.
The remaining 18 teeth are located toward the back of the mouth, functioning as premolars and molars, which are collectively known as cheek teeth. Groundhogs, like most herbivores, completely lack canine teeth, resulting in a noticeable gap between the incisors and the cheek teeth. This dental arrangement is perfectly suited to their diet of tough, fibrous vegetation, which requires extensive grinding rather than tearing.
The Design of Rodent Teeth
The incisors of the groundhog are the defining feature of its rodent classification because they are “open-rooted” and never stop growing throughout the animal’s life. This constant growth mechanism means the incisors lengthen at a steady pace, amounting to approximately 1/16 of an inch every week. This rate of elongation requires the animal to constantly wear them down through gnawing and chewing, a process known as attrition.
Their self-sharpening design is achieved by a difference in material hardness across the tooth’s surface. The front surface is protected by harder enamel, while the rear surface is composed of softer dentin. As the tooth is used, the dentin wears away faster than the enamel, automatically creating a sharp, chisel-like edge that is constantly renewed. If the teeth become misaligned and cannot grind against one another, they can grow excessively long, which can prevent the animal from eating and may eventually be fatal.
How Groundhogs Use Their Teeth
The primary function of the groundhog’s dental structure is to process the large amounts of vegetation they consume daily. The powerful cheek teeth are designed to masticate and grind down tough plant materials, such as grasses, alfalfa, and clover. An adult groundhog often consumes about one-tenth of its body weight in a single day, which helps facilitate the necessary wear on its incisors.
Beyond feeding, the groundhog’s incisors are used for excavation and maintenance of its extensive burrow system. The sharp, continually growing teeth are used as tools to loosen compacted soil and to cut through tough subterranean roots encountered during digging.