When a mysterious hole appears in a yard or garden, people often wonder if a snake is the inhabitant or the creator. While a hole can serve as a secure home for a snake, the relationship between the animal and the excavation is often misunderstood. Understanding how snakes use their environment clarifies what a hole in the ground truly represents.
Do Snakes Dig Their Own Holes
The vast majority of snake species do not possess the physical adaptations required to excavate a structured burrow. Lacking limbs or strong claws, most snakes are not considered fossorial in the way rodents or moles are. They cannot efficiently displace soil to create a permanent, engineered tunnel system.
The “snake hole” a person finds is almost always a borrowed structure, not one they constructed themselves. There are exceptions, such as specialized fossorial snakes like the shield-nosed cobra, which uses a modified snout scale for pushing into the soil. Other small species, like the Eastern worm snake, are semi-fossorial and can move through loose soil but do not dig complex burrows.
The common backyard snake is optimized for slithering on the surface or moving through existing gaps, not for head-first excavation. This reliance on pre-existing voids means any hole a snake uses was originally created by another animal or by natural geological processes. The size and shape of a snake’s shelter are thus determined by its previous occupant.
Types of Shelters Snakes Utilize
Snakes are opportunistic and readily take up residence in pre-existing cavities that offer security and temperature regulation. These borrowed spaces, which people encounter as “snake holes,” vary widely in dimension depending on their origin. Abandoned mammal burrows are a common choice, particularly those left by chipmunks, voles, or rats.
The size of these mammal-dug holes can range from dime-sized openings made by voles to openings up to three inches in diameter left by larger rodents. Snakes seek these shelters to thermoregulate, staying cool in the summer and finding insulation during the winter months. The tight fit of a small burrow also provides security from predators.
Snakes also utilize natural crevices and voids, which are irregular in shape and size. These include:
- Gaps under concrete patios or foundations.
- Spaces within rock walls or piles.
- Hollows formed by tree root systems.
- Brush piles, wood stacks, and compost heaps.
Identifying a Snake Shelter Versus Other Burrows
Differentiating a hole used by a snake from one occupied by a digging mammal relies on observing signs around the entrance. The most telling characteristic is the absence of a dirt mound, or “spoil pile,” typically found outside burrows dug by rodents or groundhogs. Since snakes do not excavate, a hole actively used by one generally has a clean, undisturbed entrance.
The size of the entrance offers another clue, often ranging from a half-inch to three inches in diameter, depending on the snake’s girth. While mammal burrows tend to be perfectly round or oval, a snake’s entry point may be more irregular, following a natural fissure or a smooth edge from repeated slithering.
The most definitive evidence of a snake’s presence is the biological material left near the opening. Look for shed skin, or “slough,” which snakes discard when they grow or to remove parasites. Snake droppings, which appear as a thick, dark, pasty smear capped with a chalky white urate, can also be found. These signs, combined with the lack of paw prints or freshly dug soil, strongly indicate a snake has claimed the space.