Twelve platypus facts, fact-checked
The platypus (Ornithorhynchus anatinus) breaks so many mammalian rules that the first specimen sent to Britain was assumed to be a hoax. Full profile in our platypus guide.
1. It lays eggs
One of only five surviving monotremes — egg-laying mammals — alongside four echidna species.
2. Males are venomous
A spur on each hind leg delivers venom powerful enough to cause excruciating, long-lasting pain in humans. Very few mammals are venomous at all.
3. It hunts with its eyes closed
Eyes, ears and nostrils shut underwater. The bill detects the electrical fields of muscle contractions in prey — electroreception, almost unknown in mammals.
4. There are no nipples
Milk is secreted through skin patches and the young lap it from the mother's fur.
5. Ten sex chromosomes
Against the usual two, and the system resembles a bird's more than a mammal's.
6. Their fur fluoresces
Under ultraviolet light platypus fur glows blue-green. The function, if any, is unknown.
7. No stomach
The oesophagus connects almost directly to the intestine — the stomach was lost in this lineage.
8. They store food in cheek pouches
Prey is collected underwater then ground at the surface using horny plates, since adults have no teeth.
9. The first specimen was thought a fake
British scientists in 1799 suspected a duck's bill had been sewn onto a beaver-like body.
10. They are a very old lineage
Monotremes split from other mammals more than 160 million years ago.
11. They are Near Threatened
River regulation, drought, habitat loss, illegal net drowning and predation by foxes and dogs have driven local declines.
12. Drought is the growing threat
Platypuses need permanent water. Longer and more severe drought under climate change is now among the most serious pressures on them.
Read the full platypus wildlife guide for IUCN status, population context and sources — or donate to WARN to help fund the partner teams protecting wildlife on the ground.
