A platypus hunts with its eyes shut, using an electric sixth sense in its bill

When a platypus dives, it closes its eyes, ears and nostrils, hunting entirely blind. Its duck-like bill is packed with tens of thousands of electroreceptors that detect the faint electrical signals produced by a shrimp's or insect larva's muscle twitches underwater. Males also carry venomous spurs on their hind legs, potent enough to cause days of agonising pain in a human — a rare combination for any mammal, venomous or egg-laying.

— Standard zoological accounts, Platypus — Ornithorhynchus anatinus