A group of sheep is commonly referred to as a "flock." This term applies to a group of sheep that are gathered together, often for herding or management purposes. Flocks can vary in size, from a few sheep to hundreds, depending on the specific agricultural or pastoral practices involved. The term can also apply to other types of birds, but when it comes to sheep, a flock signifies not just the group but also the collective nature of sheep, which typically prefer to stay close to one another for safety and companionship.