Weasels are small, highly active carnivores whose survival depends on secure, hidden dens. These slender predators require a protected space for shelter, raising their young, and caching excess prey. The entrance must be small enough to be discreet yet large enough to accommodate their long, flexible bodies.
Physical Characteristics of a Weasel Burrow Entrance
The entrance to a weasel’s den is typically small, reflecting the animal’s narrow, elongated body shape. A burrow hole is usually a tight circle or a slightly oval opening, measuring approximately one to two inches in diameter. This precise measurement allows the weasel to slip in and out quickly while excluding most larger predators.
Unlike the burrows of many other digging mammals, a weasel’s entrance often lacks a prominent pile of excavated dirt, known as a spoil mound. Weasels are meticulous about concealment and frequently use existing natural structures, minimizing the need for extensive new digging. When they do excavate, they disperse the soil over a wide area or push it into nearby cover to keep the entrance camouflaged.
The most distinguishing feature of a weasel hole is its inconspicuousness. The entrance is almost always intentionally hidden from view, tucked beneath dense ground cover or natural debris. This strategy ensures the den remains a secure retreat and a safe place for storing food caches. The tunnel itself can extend up to ten feet underground, often incorporating multiple entry and exit points for quick escape.
Preferred Locations for Weasel Dens
Weasels place a high priority on concealment and security when selecting a den site. They are highly adaptable and will choose locations that offer natural cover and proximity to a reliable food source. Common den sites include areas along riverbanks, under thick brush, or within the protective tangle of tree roots.
They frequently inhabit rock piles, stone walls, or hollowed-out logs, which provide ready-made cavities that require little modification. In residential or agricultural settings, they may establish a den beneath old sheds, patios, or near home foundations where shelter is easily accessible.
Weasels rarely dig a completely new burrow from scratch. They often take over and repurpose the abandoned tunnels of their prey, such as voles, mice, or ground squirrels. This practice means the entrance size and structure are frequently determined by the original occupant, with the weasel simply maintaining and hiding the opening.
Differentiating Weasel Burrows from Other Mammals
Identifying a weasel burrow requires excluding the holes of other small burrowers based on differences in size and surrounding features. The holes of mice and voles are typically much smaller than a weasel’s, often dime-sized for voles or around one inch in diameter for mice. The entrances of these smaller rodents are generally less clearly defined and are designed only for a single occupant.
Rats, such as the Norway rat, dig holes that are similar in diameter to a weasel’s, typically two to three inches wide, but these are often associated with worn pathways or “runs” leading away from the entrance. Rat burrows are often located near human refuse or consistent water sources, whereas a weasel’s den is focused on hunting territory. In contrast, the holes of chipmunks or ground squirrels are also small, but these animals are less concerned with concealment.
Chipmunk and ground squirrel holes are often found in open, sunny areas and may have a small, visible dirt spoil pile nearby. The weasel’s entrance, by comparison, is almost always in a highly concealed location with no obvious sign of excavation. The combined features of a small, discreet entrance and the complete absence of a dirt mound are the strongest indications of a weasel’s presence.