"Is it snowing?" Amy asked, confused as she held out her hand and let the feather-soft, downy white clumps settle on her palm. They felt surprisingly warm to the touch, unlike any snow she'd ever encountered, and they didn't melt.
"Not exactly," the Doctor replied. "It's moulting season. The natives take advantage of the warm temperatures and brisk breezes at this time of year to shed their winter coats. The loose tufts are caught in nets, then sold to other worlds for use as insulation. It's their biggest export."
"People are shedding on us?"
The Doctor beamed. "Isn't it briliant?"