The African elephant is the largest land mammal in the world. Its tusks become curved as they grow, and in males they can reach lengths of up to 350cm. Its large, triangular ears are not only perfect for collecting sound, but they are also used for releasing body heat, and elephants spread them out to intimidate other animals. African elephants usually move in herds of around 10, with the oldest female as leader. Male elephants often leave the herd around the age of 10 years, and lead solitary lives. Elephants are herbivorous and feed on leaves, branches, tree bark and fruit.