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.

Seeing photos of cold-stunned iguanas in Miami during a winter cold spell brought back an early memory. I was a seventh-grade intern in the reptile house at Audubon Zoo in New Orleans, when I jumped ...