The grass snake, scientifically known as Natrix natrix, is a non-venomous reptile widely distributed across Europe and parts of Asia. It is often found near water sources like ponds and rivers, which is reflected in its alternative name, the ringed snake. Yes, the grass snake possesses teeth, but it is entirely harmless to humans. It is an aglyphous species, meaning it lacks the specialized fangs used for venom delivery. Its primary defense is not an aggressive bite.
The Structure of Grass Snake Teeth
The dentition of the grass snake is characterized by a type known as aglyphous, which means it does not possess specialized hollow or grooved fangs. Instead, this snake has numerous, solid teeth that are structurally similar across the upper and lower jaws. These teeth are small, sharp, and distinctly recurved, curving backward toward the snake’s throat. The teeth are designed for grasping and securing food, not for chewing, as snakes swallow their prey whole. They are anchored to several bones in the mouth. New teeth are continuously replaced throughout the snake’s life.
How the Teeth Function During Feeding and Defense
The recurved shape of the grass snake’s teeth is a highly effective adaptation for its diet, which primarily consists of slippery animals like fish and amphibians. Once the snake grabs its prey, the backward-pointing teeth prevent escape and facilitate “walking” the prey into the esophagus. The snake uses its independently moving jaws to slowly pull the item toward the throat. This mechanism is purely for manipulation and swallowing, not for mastication.
Defensive Behavior
Grass snakes rarely bite, preferring to flee or use other deterrents first. While they are capable of biting defensively, the teeth are not designed to inflict medically significant injury to a person. A defensive bite typically results only in superficial scratches or pinpricks, as they lack the large fangs of venomous species. Their first line of defense is usually thanatosis, or playing dead, often accompanied by the release of a foul-smelling fluid from the anal glands.
Distinguishing the Grass Snake from Other Species
Identifying the grass snake is important, especially in regions where venomous snakes like the adder (Vipera berus) might also live. The most distinguishing physical feature is the characteristic yellow or cream-colored collar, sometimes ringed with black, located just behind the head. This marking gives the species its alternative common name, the ringed snake. The grass snake typically has an olive-green to brownish-gray coloration on its back, sometimes with black bar-like markings along the sides.
Visual Differences from the Adder
Unlike the adder, which has a distinct dark zigzag pattern running down its back, the grass snake is generally more slender and elegant in appearance. The grass snake has a round pupil, whereas the adder has a vertical, slit-like pupil. These visual cues, along with its preference for aquatic habitats, help confirm that the snake is the harmless Natrix natrix.