Rattlesnakes do not create their own holes because they lack the necessary anatomy to excavate soil. Instead, they rely on existing natural or man-made structures for shelter, such as abandoned mammal burrows, rock fissures, or spaces beneath logs and concrete slabs. Identifying these entrances is important for public safety, especially in warmer months when snakes are most active.
Rattlesnake Shelter vs. Rattlesnake Den
The term “rattlesnake hole” refers to two distinct locations that serve different biological purposes. A rattlesnake shelter is a temporary refuge used by a solitary snake for cover during the active foraging season. This might be an abandoned rodent burrow or a space beneath a flat rock, providing protection from predators and temperature extremes.
A rattlesnake den is a location used for long-term brumation during the cold winter months. These sites are typically deep rock crevices, talus slopes, or burrows that extend below the frost line to maintain a stable, non-freezing temperature. Dens are often communal, with dozens or even hundreds of snakes gathering together to survive the winter. Snakes often return to the same den year after year, demonstrating strong site fidelity.
Key Visual Indicators of a Rattlesnake Entrance
The most telling sign of rattlesnake use is the nature of the entrance itself. Since snakes cannot excavate, there will be no mound of freshly dug dirt surrounding the opening. The entrance shape is often irregular, reflecting the natural fissure or original burrow structure, and may appear wider than it is tall or slightly oval. The size can vary significantly, depending on the number and size of the resident snakes.
The ground surface around an active entrance may exhibit a smoother, worn appearance caused by the repeated slithering of snakes entering and exiting the space. This subtle polishing contrasts sharply with the rougher texture of undisturbed soil or rock. A positive confirmation of a snake’s presence is the discarded shed skin (slough). Finding a clear, intact shed skin near the entrance is a strong indicator of a recent resident.
Another clue is the presence of snake droppings, which look distinctly different from mammalian scat. Snake feces are typically a thick, dark brown or black paste, often capped with a chalky white deposit of uric acid. Snakes spend time basking near the den entrance in the spring, especially on south-facing slopes that receive ample sun exposure. This behavior helps them regulate their body temperature before they disperse to their summer foraging grounds.
Mistaken Identity: Distinguishing Rattlesnake Shelters from Rodent Burrows
The most common mistake is confusing a rattlesnake shelter with an active burrow created by a gopher, ground squirrel, or prairie dog. Rodent burrows are characterized by a mound of freshly excavated dirt piled immediately outside the opening. This pile of “tailings” is a clear sign of an animal that actively digs, which rattlesnakes do not do. Rodent holes also frequently show small claw or paw prints in the soft dirt around the rim, which are absent at a snake’s entrance.
The structure of the opening can also offer a distinction. Many rodent burrows, particularly those of pocket gophers, are perfectly circular and relatively uniform. In contrast, a rattlesnake shelter entrance is often defined by an existing rock structure, abandoned root system, or a crack, leading to an irregular, non-symmetrical opening. Rodents may also incorporate nesting material like shredded plant matter, paper, or fibers near or inside the entrance. If a potential den is identified, the safest protocol is to maintain a distance of at least six feet and observe the area without disturbing the entrance.