Sheep were domesticated between 9000 and 11000 years ago and they are found anywhere humans are as they are adaptable to different habitats and humans use them for many things - from wool to meat. They tend to flock together as a survival tactic - so predators cannot easily pluck one on its own. In fact, sheep become very stressed when separated from their herd members. Sheep can be very destructive grazers, and can cause a lot of damage. However, sheep are an environmentally friendly help in forestry, agricultural clearing as well as just mowing your lawn as long as they are left to graze for a short period of time.