One of the things that make humans truly alien ... facial hair (from "Pretender"):
Bren rubbed his stubbled chin and got his razor from his kit, down between his feet, with his computer. The razor still had enough charge to shave with, and he did that, while Cajeiri visited the accommodation to the rear.
He was still shaving when the boy came back and sat fown, and watched in curiosity.
"Can it grow as long as your hair, nandi?" the boy asked.
"It might, young sir. But one has no wish to scandalize the court."
"Will you do it sometime?"
"Grow it that long?"
"Much too uncomfortable, young sir. And not at all becoming. And it grows just as slowly as hair on your head."
"You would be as odd as the kyo."
"That I might, young sir. But by no means as round."