Monotremes are a unique group of mammals that lay eggs instead of giving birth to live young. This group includes fascinating animals like the platypus and the echidna. Unlike most mammals, monotremes have a cloaca, which is a single opening for excretion and reproduction. They are primarily found in Australia and New Guinea. These egg-laying mammals have some unusual features. For example, the platypus has a duck-like bill and webbed feet, while echidnas have spiny coats and long tongues for catching insects. Monotremes are a rare link between reptiles and mammals, showcasing the diversity of life on our planet.