Tails might look like nature’s afterthought but for many animals, they’re multitasking power tools. Whether it’s balancing, fighting, flirting, or escaping predators, tails do way more than just wag.

Platypuses are weird looking. They look like someone stitched together a duck and a beaver—flat bill, webbed feet, and a broad tail. But their appearance isn't even the strangest thing about them. Not ...