The platypus is the only Australian mammal that lays eggs and has a duck-like bill.
Platypuses are semi-aquatic monotremes found in freshwater rivers, streams, and lakes of eastern Australia, including Tasmania. Females lay soft-shelled eggs, then nurse the hatchlings with milk released through skin openings rather than through nipples. The young feed from milk pooled in specialized fur.
The broad bill is sensitive to electrical signals and movement in water, helping the platypus locate prey such as aquatic insect larvae, worms, and small crustaceans while its eyes, ears, and nostrils are closed underwater. Webbed feet aid swimming, while claws help with digging and movement on land.
Male platypuses have a venomous spur on each hind ankle, but the animal is not generally aggressive toward people. The platypus is one of only two living monotreme lineages; the other is the echidna group, also native to Australia and New Guinea.