The platypus lives in rivers and lakes across eastern Australia and Tasmania. It has webbed feet, a broad flat tail, dense, brown fur and a broad, rubbery, duck-like bill which it uses to probe for food—worms, shrimps, insect larvae and crayfish—on the muddy bed. It lives in a water burrow dug out of the river bank. Instead of giving birth to live young, as almost all other mammals do, the platypus lays eggs.

Hatchlings

Their young are born inside soft-shelled eggs. These hatch after a few days, and the under-developed young are suckled (fed on milk) until they have developed fully. The newly hatched young are blind and hairless, and are fed by the mother's milk. The platypus has no teats; instead, milk is released through pores in the skin.

Monotremes

The platypus belongs to the group of mammals known as monotremes. These are the only mammals that lay eggs instead of giving birth to live young, as marsupials and placental mammals do. There are five species of monotremes: four species of echidna and the platypus. They live only in Australia and New Guinea.

Echidna

The echidna, or spiny anteater, has a long, thin snout and powerful claws for digging. Its body is covered in fur and sharp spines. It feeds on ants, termites and worms, crushing them between its tongue and the roof of its mouth.

Spring is the breeding season for the echidna. As temperatures rise, they emerge from hibernation. Males search for a female and pursue her. During courtship, a single female may be followed by a “train” of up to ten males.

After mating, the female lays a single egg and tucks it into a pouch on her front. Ten days later, the young echidna hatches. It stays in its mother’s pouch, licking up milk which seeps into her fur, until it becomes too prickly.