The platypus lives in rivers and lakes in eastern Australia. During the day it sleeps in a hole at the edge of the water. It rises at dusk and dives into the water to look for food. The platypus is a fantastic swimmer. It has a big flat tail, webbed front feet, and waterproof fur. While diving the animal shuts its eyes, nose and ears completely and can stay underwater for up to 10 minutes. A carnivore, the strange mammal eats shrimp, crayfish and other creatures that live on the bottom of the river. Occasionally it also feeds on frogs, fish or insects. Its special sensors enable it to hunt underwater and in the dark. When living creatures move, their muscles generate electricity. The platypus has special organs that can sense this. It can also feel changes in water pressure. Using the two senses together, the platypus can sense something move and swoop to catch it. The animal is unusual in other ways, too. Although it is a mammal, it doesn't give birth to live young. Rather, it lays eggs just like birds. This is clearly no ordinary creature! The platypus has been around for a very long time. Archaeologists have found its ancestor's fossils from 110 million years ago. They think these primitive mammals may have appeared as long as 144 million to 206 million years ago during the Jurassic Period, when giant dinosaurs ruled the Earth. A Joke That Wasn't When Western scientists first saw a platypus they thought someone had put together different animal parts as a joke. This is because the animal has the bill and webbed feet of a duck, a beaver's tail, and an otter's body and fur. When scientists realised these are mammals that lay eggs, they were even more confused. One Playpus, Two ... Plurals can be complicated in English. Most of the time you just add an 's' like cats, dogs, birds, and lizards. But there are exceptions. The plural of 'sheep' is sheep, and the plural of 'cactus' is cacti. Scholars argue over the plural of 'platypus'. Some say the correct word is platypodes but most people say platypuses or just platypus. The one thing they all agree on is that you can't have two platypi. Why Platypuses Are Not In Your Zoo Keeping the animals is not easy. They need a fast-flowing river in which to hunt, and a large underground home. As they don't live in groups, you need a lot of space for each animal. They also breed very rarely in zoos. Because of this, Australia doesn't allow other countries to import them. You don't need to go to Australia to see them, however, because you can see them online. Just visit Brisbane's Lone Pine Koala Sanctuary at www.koala.net . Watch Out! The platypus looks cute, but the males have a poisonous spur on their back paws. This poison is strong enough to kill small animals but not people. However, it is very painful. If you get scratched, you will scream for a doctor. Fab Fact The Australian 20 cent coin has a picture of the platypus on one side and a picture of Queen Elizabeth II on the other. A hundred years ago, the platypus was hunted for its fur. It became quite rare. Today this mammal is protected, and there are plenty of them living in the wild again.