“The platypus is the most touchy, temperamental, unpredictable animal,” says Australia’s David Fleay, and he should know. Called “the platypus man,” Fleay is the world’s leading ...

Gunjan Pandey CC BY-SA 4.0 via Wikimedia Commons Between backward-facing-feet, nipple-less milk secretion and egg-laying, platypuses and echidnas are some of the strangest mammals on Earth.