High altitude blanket bogs are one of Northumberland's unusual habitats. The bogs have been created over thousands of years by the action of glaciers making hollows where water and organic matter collects. They are home to one of Whitelee's spring extravaganzas - fields full of cotton grass. It's not really a grass, but a type of sedge. The fluffy tips are the seed heads, not flowers. People have tried to weave the fluff into material, but the strands are just too short to make anything useful.