Badger holes are complex, multi-generational subterranean homes known scientifically as setts. This elaborate architecture is central to the survival of the badger clan, providing shelter, a secure place for hibernation, and a nursery for new cubs. A badger sett is a permanent feature in the landscape, often used and expanded by successive families for decades or even centuries, making it one of the most significant burrows created by any mammal. The size and structure of this underground dwelling offer protection from predators and regulate temperature year-round.
The Entrance and Tunnels
The most visible part of a badger sett, the entrance hole, offers the first clue to the size of the animal within. Unlike the round holes of a rabbit or the cleaner, narrower tunnels of a fox, a badger entrance is typically a sideways oval or D-shape, reflecting the badger’s broad, stocky body. These openings are consistently sized, measuring approximately 30 centimeters (12 inches) wide and 25 centimeters (10 inches) high, allowing the animal to pass through comfortably.
A key identifying feature of an active sett is the presence of a spoil heap, a substantial mound of freshly excavated earth and stones situated immediately outside the entrance hole. This material is a byproduct of the badgers’ constant digging to expand and maintain the tunnel network. The initial tunnels typically slope downward, often following the contours of the ground to aid with drainage and air circulation. The diameter of the main tunnels remains close to the entrance dimensions, usually around 30 centimeters.
Internal Structure and Depth
The architecture beneath the entrance is a sophisticated network that expands far beyond a simple burrow. A well-established main sett can encompass hundreds of meters of tunnels and spread over an area exceeding 2,000 square meters. Tunnels often run at varying depths, but the main living areas are strategically placed to ensure stability and consistent temperature.
The primary nesting chambers, which are larger than the tunnels, are typically located at least 2 meters below the ground surface, though tunnels themselves can reach depths of up to 4 meters in certain soil types. These chambers are lined with fresh bedding material like hay, grass, or bracken, which badgers drag in backwards and regularly change for hygiene and insulation. The complex system includes smaller side tunnels and occasional ventilation shafts that extend to the surface to facilitate airflow.
Types of Setts and Their Scale
The term “badger hole” can refer to four distinct types of setts, each varying significantly in size, complexity, and function. The Main Sett is the largest and most complex, forming the center of the badger clan’s social life and territory. It is continuously occupied, used for breeding, and can feature anywhere from 8 to over 40 active entrances.
A secondary structure is the Annex Sett, an intermediate-sized system located within 50 to 150 meters of the main sett and connected to it by well-defined paths. Annex setts are also regularly used, often seasonally, and may serve as a secondary breeding location in larger clans. Beyond these are the Subsidiary and Outlier Setts, which are much smaller and less frequently used. Outlier setts are the smallest of the structures, typically featuring only one or two entrances and minimal spoil heaps. These are used sporadically by a single badger or a small group as temporary rest stops during foraging trips.