A few weeks back, we examined why fingernails grow so much faster than toenails. Now comes the explanation for another bodily-function quirk you’ve always kinda wondered about, courtesy of the SciShow’s Hank Green: How does hair (including, like, eyebrow and armpit hair) know when to stop growing?
https://gizmodo.com/why-do-fingernails-grow-so-much-faster-than-toenails-1695886809
