This very unusual animal has webbed feet, the forefeet are used for swimming, the back feet as brakes and for steering. The adult male has a sharp hollow spur on each ankle, this spur produces venom possibly lethal to small mammals, and very painful for humans.

The bill of the Platypus is soft and very sensitive, the skin of the bill has touch receptors which is used to receive information about its surroundings and is also sensitive to the slight electric currents generated by its prey. The eyes, ear apertures and nostrils are closed whilst under the water.
The fur is long and sleek on top, but underneath is an extremely thick underfur which remains dry.

Food is collected in the water, being mainly invertebrates, both larval and adult, it is sifted from the bottom, stored in large cheek-pouches until it surfaces where whilst resting the food is broken up between the tongue and the horny grinding plates and shearing ridges on the upper and lower jaws. Larger prey are eaten individually.

Breeding occurs in Northern NSW area around September, the female will lay 1 or 2 eggs which she incubates against her abdomen for about 2 weeks, she will at this stage be inside a blocked off nest at the end of a long burrow called a breeding burrow. The young Platypus will suckle the mother for 4 months, milk is exuded from the abdomen, they have no teats. After weaning the young become independent, and disperse.
The infant Platypus has milk teeth, but these are not replaced when shed. It is interesting to note that fossils found, indicate that the Platypus had better developed teeth that were not shed.