The musk ox is a social animal and they live together in big herds, consisting of a leading bull, females and calves of different ages. The surplus males form small herds.
In contrast to a lot of other animals, the musk ox doesn't flee if attacked by a wolf pack or the like. Instead they form a front against the wolves with the adult animals in the front and the calves and you animals protected in the middle. A musk ox is very strong and a wolf that comes to close will risk being speared on their horns or trampled to death.
The musk ox's thick fur consists of a long outer coat and a thick wolly under coat. The outer coat is water repellent, while the thick under coat protects against even the worst arctic cold. The musk ox can live in areas with temperatures down to -40oC.
The musk ox is actually not a cow although the name implies it. The musk ox is more closely related to sheep and goats than to cows.