Echidnas ,also known as spiny anteaters,are four extant mammal species belonging to the Tachyglossidae family of the monotremes, an order of egg laying mammals. Together with the Platypus, they are the only surviving members of that order comprising the only extant mammals that lay eggs.Although their diet consists largely of ants and termites, they are only distantly related to the true anteaters of the Americas. They live in New Guinea and Australia. The echidnas are named after a monster in ancient Greek mythology.