A badger sett is an underground tunnel system that badgers dig and use as a permanent home. Think of it as a sprawling burrow network with multiple entrances, connecting tunnels, and separate chambers for sleeping, raising cubs, and even toileting. Some setts are modest, with just a handful of holes. Others are enormous engineering projects passed down through generations of badgers for hundreds or even thousands of years.
Inside a Badger Sett
Setts vary enormously in size, but the basic layout follows the same pattern: entrance holes lead into tunnels that branch and connect to rounded chambers used for nesting and sleeping. A study that physically excavated three setts in England found dramatic differences in scale. The smallest had just 16 meters of tunnels, one chamber, and five entrances. A mid-sized sett contained 140 meters of tunnels, nine chambers, and 42 entrances. The largest, a well-established main sett, had 879 meters of tunnels (nearly a kilometer), 50 chambers, and 178 entrances.
Tunnels in smaller setts typically run at a single level, averaging about one meter below the surface. Larger setts often expand onto two levels, with a shallower layer around 50 centimeters deep and a deeper layer at roughly a meter or more. The construction effort involved is staggering. Across those three excavated setts, badgers had removed an estimated 70 tonnes of soil to create around 45 cubic meters of underground space.
Inside the chambers, badgers line their nests with bedding material, mostly dry grass, leaves, bracken, and straw. They regularly collect fresh bedding and replace old material, a task that can take an hour or more per session. Bedding collection tends to increase from autumn through winter as badgers prepare for the colder months and the arrival of cubs. Main setts also contain latrine areas, essentially underground toilet spots, which smaller setts may lack.
Types of Setts
Not every sett is the same, and badger groups typically maintain several across their territory. Researchers classify them into a few categories based on size and usage.
- Main sett: The group’s headquarters, used year-round. Rural main setts average nearly 20 entrance holes and are occupied continuously by at least some members of the group. This is where the dominant female typically raises her cubs.
- Annexe sett: Located close to the main sett and connected by well-worn paths. These are used regularly but not as consistently.
- Subsidiary sett: Farther from the main sett, used more sporadically. Males tend to spend more time in subsidiary setts than females do.
- Outlying sett: The smallest and most distant, often with just one to three entrance holes. These may only see occasional use.
A typical badger group maintains an average of four outlier setts alongside their main sett. Subordinate females sometimes use secondary setts to raise their own cubs away from the dominant female, particularly during breeding season. Usage of these satellite setts shifts with the seasons, with greater activity during summer months.
Where Badgers Build
Badgers are selective about where they dig. They prefer sloped ground, which makes soil removal easier during excavation and improves drainage so the sett doesn’t flood. Deciduous woodland is the favored habitat, chosen more often than coniferous forest, mixed forest, or open land. The presence of nearby trees, rocks, and dense ground vegetation all correlate with sett location, likely because these features provide cover and structural stability for the tunnels.
Badgers also avoid areas with heavy human disturbance. Setts are less common in landscapes that see frequent activity at both low and high altitudes. Soil type matters too: loose, well-drained soil is far easier to excavate than heavy clay or waterlogged ground, which is why sandy or loamy soils on wooded hillsides are classic sett territory.
How Long Setts Last
One of the most remarkable things about badger setts is their longevity. Because each generation inherits and expands the tunnels dug by previous occupants, setts accumulate size and complexity over time. Many known setts in the UK are hundreds of years old. According to the Badger Trust, some are thousands of years old. Excavations of a sett in the Czech Republic suggest badgers may have occupied that site for as long as 100,000 years, excluding periods covered by ice ages. A large main sett is essentially an ancestral home, continually renovated and expanded by the badgers living in it.
How to Spot an Active Sett
From above ground, a badger sett looks like a cluster of large holes in a bank or hillside, often surrounded by mounds of excavated earth. The entrance holes are distinctively shaped: wider than they are tall, roughly the size of a large dinner plate, reflecting the badger’s broad, low body. Several signs indicate a sett is actively in use:
- Fresh spoil heaps: Piles of recently dug soil outside entrances, often with claw marks visible.
- Bedding material: Dry grass, leaves, or other nesting material visible near entrances, sometimes dragged out for airing.
- Worn paths: Well-trodden trails leading between entrances or radiating outward into the surrounding habitat.
- Latrines: Shallow pits near the sett used as communal toilets.
- Hair: Coarse black-and-white badger hairs caught on the edges of entrance holes or nearby fencing.
- Footprints: Broad prints with five toes and long claw marks in soft ground near entrances.
If even one entrance shows signs of current use, the entire structure is considered an active sett.
Other Animals That Use Setts
Badger setts attract other wildlife. Camera trap studies at main setts have recorded foxes, wild boar, rabbits, stone martens, genets, and mongooses visiting or entering the tunnels. Foxes are the most well-known cohabitants and will sometimes occupy a disused section of a large sett simultaneously with badgers. Rabbits also dig into the periphery of established setts. For these species, badger setts offer ready-made shelter that would be costly to excavate from scratch.
Legal Protection in the UK
Under the Protection of Badgers Act 1992, a badger sett is legally defined as “any structure or place which displays signs indicating current use by a badger.” The law makes it an offense to damage or destroy a sett, block any entrance, send a dog into a sett, or disturb a badger occupying one. These protections apply whether the interference is intentional or reckless. In Scotland, any activity that could interfere with a sett requires a license from NatureScot.
This legal definition is deliberately broad. It covers not just the obvious main sett with dozens of holes but also a single outlying entrance that shows signs of recent badger activity. If you’re planning construction, landscaping, or forestry work and find holes that could be a sett, the presence of any field signs like fresh digging, bedding, hair, or footprints is enough to trigger legal protection.