Muskox, or Musk-oxen, live in the frozen Arctic and roam the tundra in search of the roots, mosses, and lichens that sustain them. During winter they use their hooves to dig through the snow to graze on these plants. During the summer they supplement their diet with grasses and Arctic flowers, generally feeding near water. They are herd animals, forming groups of two or three dozen animals and sometimes led by a single female. Their numbers are used to deal with predators, joining together to "circle the wagons" around the herd to protect their young. Muskox are able to survive arctic conditions because of their long shaggy hair that is formed of two coats.