We have two Great Pyrenees and they're indeed great. They work as a team to keep predators away with one patrolling a perimeter while the other usually stays close. The outer one engages and the inner one barks to let the predator know which way not to go. We have lots of coyotes which keep their distance and rarely lose a chicken. They leave the deer alone and seem to be able to distinguish predators, possibly due to the forward set eyes. They even keep an eye on hawks above and bark at any that land in a nearby tree. Expect quite a bit of barking at night because that is what they do to keep things away. From morning to mid day they sleep and that is when any remaining predation will happen by a smart coyote or coon that figures out their routine.