How is an echidna and a platypus compared?

They are both monotremes, the only egg-laying mammals. While they lay eggs like birds and reptiles, they have mammary glands with which to feed the young. A very odd order, and are only found in Australia. read more

Both the male platypus and the male echidna have a spur on their hind ankle, but the platypus's is poisonous whilst the echidna's serves no known function. Neither echidnas nor platypuses have teeth. The platypus grinds its food between bony plates in its bill, whilst the echidna uses its long, sticky tongue to catch and eat termites and ants. read more

Early researchers were misled by two factors: firstly, monotremes maintain a lower average temperature than most mammals; secondly, the short-beaked echidna, much easier to study than the reclusive platypus, maintains normal temperature only when active; during cold weather, it conserves energy by"switching off" its temperature regulation. read more