The presence of a hole in the landscape often prompts curiosity and concern about the animal residing within. While many people refer to these openings as “snake holes,” this phrase often misrepresents the nature of a snake’s shelter. A snake’s relationship with an underground cavity is one of opportunistic tenancy rather than construction. The shelter provides a microclimate for regulating body temperature, avoiding predators, and occasionally ambushing prey. Understanding what a snake uses for shelter requires focusing on the subtle evidence left by the animal that moved in, rather than the animal that dug the hole.
The Truth About Snake Burrows
Most snake species are anatomically unsuited for excavating their own burrows because they lack the necessary limbs and digging appendages. Instead, these reptiles are highly opportunistic, relying almost entirely on existing defects or structures in the environment. They readily take over abandoned burrows created by rodents, tortoises, crayfish, or other small mammals. They also utilize natural features such as deep rock crevices, root channels, or spaces beneath logs and concrete slabs.
A few rare exceptions exist in the form of specialized fossorial snakes, which are adapted for a subterranean existence. Species like the Hognose snake, with its upturned snout, or various Sand Boas, are equipped to push and tunnel through very loose, sandy soil. However, the vast majority of holes encountered are not the result of a snake’s specialized excavation. The distinction is important, as the characteristics of a snake-used shelter are defined by the absence of digging activity.
Key Visual Clues for Shelter Identification
The most telling sign that a hole is used by a snake is the lack of fresh, excavated soil piled around the entrance. Animals that actively dig, such as gophers or moles, consistently deposit loose dirt near the opening, but a snake tenant leaves a clean threshold. A snake-used opening is often irregular in shape, perhaps oval or slightly angled, due to its formation around natural obstacles like roots or rocks. The entrance typically appears smooth or compacted, a result of the snake’s repeated slithering movement in and out of the shelter.
Physical evidence provides reliable confirmation of a snake’s presence. Look for shed skin, known as ecdysis, which a snake discards as it grows or to remove external parasites. Snake droppings, which are cylindrical with a characteristic white, chalky urate cap, may also be found near the opening. Subtle, wavy lines or drag marks in the fine soil or dust surrounding the hole can also indicate a snake has recently passed through, as they leave no distinct footprints.
Identifying Common Look-Alikes
Differentiating a snake’s shelter from that of a digging mammal involves identifying the specific signs of the original excavator. Rodent and gopher holes are frequently surrounded by a noticeable mound of freshly dug soil, sometimes forming a horseshoe shape where the animal kicked out the dirt. Active rodent holes may also contain nesting debris, such as shredded plant material or fabric, and may be plugged with soil to block the entrance. These openings are typically circular and can range in size from one to four inches in diameter, similar to the holes a snake might occupy.
Another distinct look-alike is the crayfish burrow, which is identified by its unique construction. Burrowing crayfish, which live in areas with a high water table, build characteristic mud “chimneys” or towers above the entrance. These structures are composed of small, pelletized mud balls that the crayfish carries up from the subterranean tunnel. The presence of this stacked mud tower in saturated or wet areas suggests a crayfish is the resident, not a snake. Small lizard or amphibian burrows, while sometimes used by snakes, are typically narrower and may be located near water sources or within soft, damp soil.
Safety and Observation When Finding Shelter
Upon encountering a suspicious hole, maintain a distance of several feet and observe the area carefully. Never attempt to poke, probe, or reach into the opening, as this can provoke a defensive strike from any animal inside. The hole may be a seasonal shelter, or hibernaculum, which snakes use to survive cold weather. These underground chambers are thermally stable, keeping the reptiles below the frost line where temperatures remain above freezing.
These communal overwintering sites are sometimes established in abandoned animal burrows, rock piles, or foundation cracks. Snakes will return to the same hibernaculum year after year, dispersing when temperatures consistently rise in the spring. If the hole is near a home and its occupancy is a concern, monitoring the entrance using a light layer of flour or fine sand can reveal sinuous tracks without disturbing the potential occupant.