Although such a familiar species, few people have actually seen this elusive nocturnal mammal in its natural habitat (2). During the day badgers are inactive, and rest in their setts, complex systems of underground tunnels with nests of dry grass, straw and dead leaves (2), which are passed on from generation to generation (6). In certain conditions they may forage during the day, for example during hot summers when food is in short supply (7). Although they do not hibernate, they do spend a lot of time in the sett during cold spells in winter (7).
Badgers are omnivorous; their main source of food is earthworms, of which they may eat several hundred a night (6). They also take other invertebrates, nuts, fruit, small vertebrates, bulbs and cereals (7). They are one of the few species able to kill and eat hedgehogs (Erinaceus europaeus), thanks to their thick skin and long claws (6).
Badgers tend to live in social groups consisting of a number of adults and young (5). There is usually a dominant male (boar) and one breeding female (sow) in each group (5), but occasionally more than one female breeds (2). The dominant boar marks the range with dung in certain places called 'latrines', and will fiercely defend his range from intruding males (5). Mating tends to occur in the spring, but it can take place throughout the year. Regardless of the time of year of fertilisation of the egg, further development is delayed until December (7). This 'delayed implantation' means that there is an opportunity for cubs to grow sufficiently before winter (5). Litters contain between 1 and 5 playful cubs, which become sexually mature at around 2 years of age (5).