Snakes inhabit diverse environments, and their secretive nature often raises questions about their subterranean habits. Understanding how these reptiles use underground spaces reveals insights into their survival strategies and ecological roles. This article explores whether snakes actively dig and why they seek refuge underground.
Are Snakes True Diggers?
While many snake species are found in underground spaces, the majority do not actively construct extensive burrows from scratch. Most snakes opportunistically use existing holes, crevices, or burrows excavated by other animals like rodents, gophers, or armadillos. They may inhabit abandoned dens or even take over active ones, sometimes consuming the previous occupant. This behavior allows them to conserve energy and find ready-made shelter.
A specialized group, known as fossorial species, are true burrowers with unique adaptations for digging. These snakes often have pointed or wedge-shaped snouts and small, sometimes nearly undetectable, eyes, suited for pushing through soil. Examples include blind snakes, thread snakes, and hognose snakes, adept at navigating loose soil, sand, or leaf litter. Hognose snakes use their upturned rostral scale to shovel dirt, creating tunnels. Blind snakes, also called worm snakes, use their pointed snouts and cylindrical bodies to burrow through soil and ant or termite nests for food.
Why Snakes Seek Underground Shelter
Underground spaces provide valuable benefits for snakes, whether they dig their own or not. A primary reason is thermoregulation, as the subterranean environment offers a stable temperature buffer against extreme heat or cold. Being ectothermic, snakes rely on external heat sources, and burrows allow them to escape scorching surface temperatures or freezing winter conditions. During colder months, many species enter brumation, seeking underground dens (hibernacula) deep enough to remain below the frost line.
Burrows also offer protection from predators, allowing snakes to hide while resting or digesting meals. These concealed locations are also used for ambush hunting, enabling snakes to lie in wait for unsuspecting prey, particularly rodents. Furthermore, underground spaces provide a safe, humid environment necessary for shedding their skin, a process during which snakes are more vulnerable. For many species, burrows serve as nesting sites for laying eggs, offering a secure and stable environment for offspring development.
Spotting Evidence of Snakes Underground
Identifying a snake-occupied burrow often requires careful observation, as snakes primarily use holes made by other animals. Snake holes typically have smooth, uniform entrances, ranging from half an inch to three inches in diameter, without large piles of excavated dirt nearby. This smooth edge distinguishes them from rodent burrows, which often show claw marks, scattered dirt, or debris like nesting materials.
Other clues can indicate a snake’s presence, such as discarded snake skins near a burrow entrance, as snakes shed periodically. Snake droppings, typically dark, cylindrical, and with a white, chalky cap, can also be found. Fresh, wavy tracks in the soil leading to or from the hole suggest recent snake activity. If a hole has spiderwebs or debris, it is likely unoccupied. When observing potential snake habitats, always maintain a safe distance and avoid disturbing the area.