The badger is the largest member of the Mustelid family and Britain's largest land carnivore. They are nocturnal, emerging at dusk in summer to spend the night foraging. In winter they are much less active but do not hibernate. They live in social groups of 4 - 12 adults and lie up in an extensive system of underground tunnels and nesting chambers known as a sett. The female is called the sow, the male the boar. Earthworms make up 50% of the diet, which also includes insects, bulbs, small mammals, blackberries, grain, carrion and windfall fruit.