Snakes often inhabit the underground world, yet the capability of excavating a tunnel is not universal across all species. They generally fall into two categories: those that actively dig their own burrows and those that opportunistically use existing structures. The ability to shift soil requires specific physical modifications, meaning only a specialized group of snakes can truly be called subterranean architects. This distinction helps explain how different species interact with their environment and survive harsh conditions.
Yes, But Only Specific Species
A select number of snakes are true fossorial burrowers, possessing the specialized anatomy required to create their own holes. These active diggers represent a small, highly adapted minority within the snake world. Species such as the Eastern hognose snake, the Florida pine snake, and various sand boas are highly effective at moving earth.
For these snakes, digging is a survival behavior driven by environmental and dietary needs. They burrow to regulate their body temperature and humidity, providing a stable environment shielded from surface extremes.
Dietary Burrowing
Many worm snakes and blind snakes spend almost their entire lives beneath the surface, digging to pursue specialized subterranean prey like insect larvae, ants, and termites. The hognose snake, for example, uses its upturned snout primarily to dig for toads, which form a major part of its diet.
Specialized Anatomy for Excavation
True burrowing snakes possess several anatomical features that facilitate moving soil. The most noticeable adaptation is the shape of the head, which is often blunt, narrow, and no wider than the neck, creating a streamlined profile for pushing through substrate. This compact skull acts as a reinforced ramming tool, allowing the animal to push its head forward and move the surrounding soil away.
The snout is frequently modified into a shovel-like structure, such as the prominent, upturned rostral scale found on hognose snakes, which functions like a small plow. The Western shovelnose snake uses a long, probing snout to thrust into soft sand, allowing it to thread its body through and enlarge the initial opening. Their scales are also smoother and more rigid than those of surface-dwelling species. This reduces friction and protects the body from abrasion as they move through rough soil. Some fossorial snakes have evolved a unique spherical vestibule in their inner ear, enhancing their ability to detect subtle low-frequency vibrations from subterranean prey.
Utilizing Pre-Existing Tunnels and Burrows
While few species are proficient excavators, the vast majority of snakes are opportunistic users of existing structures. These snakes rely on infrastructure created by other animals or natural geological processes for shelter. They commonly take up residence in abandoned burrows dug by rodents (like gophers, chipmunks, and voles) or in tunnels created by turtles and crayfish.
This opportunistic use of existing burrows is a widespread strategy for thermoregulation and protection. Snakes use these spaces to escape predators, shelter from extreme heat or cold, and survive the winter months in a state of dormancy known as brumation. Species like gopher snakes and milk snakes frequently use rodent burrows, sometimes consuming the original occupant before settling in.