These are systems of interlocking tunnels with nest chambers, toilets, and several entrances. Badgers inherit setts from their parents generation after generation, while always expanding and refining them. The result is huge tunnel systems that are, in some cases, actually centuries old. Through radiotracking it has been determined that this is due to delayed dispersal, resulting in family groups remaining together. Females are even less likely than their brothers to leave the sett in which they were born.
Clans often consist of a dominant male, a dominant female, and their subordinate offspring.
The dominant pair are generally the only individuals that successfully produce cubs, although all or most of the females mate with the dominant male. Subordinate females often become pregnant, but on the few occasions when the pregnancy is carried to term the dominant female generally finds and kills the resultant cubs. Although it is difficult to observe badgers since they are only above ground at night, it seems clear that subordinates do not bring food to the nest for the breeding female or her cubs. They do, however, participate in sett excavation and the airing of nest material, but not at significantly higher rates after the birth of a litter. They delineate their territories by placing latrines, areas where all clan members urinate and deficate, at regular intervals along the borders.