Beasts of burden are animals that have been used for centuries to carry goods and people over long distances. Llamas, MULES, YAKS, LADEN, OXEN, ASSES, and camels are all examples of beasts of burden. Llamas are a domesticated species of South American camelid, while MULES are a hybrid of a male donkey and a female horse. YAKS are large, long-haired bovines native to the Himalayas. LADEN is an adjective meaning loaded with a heavy load. OXEN are domesticated bovines used as draft animals in many parts of the world. ASSES are members of the horse family, and camels are large mammals with distinctive humps found in desert areas. Finally, RULES are regulations or guidelines that must be followed.