A sheep is lost without it's flock, separate it from is companions & it will quickly become disorientated , unhappy , panic stricken,& prone to be picked off by predation totally incapable of acting on it's own, the only defence it does have is the flight mode!
When amongst it's flock it blindly follows the leader even at the expense of following the majority over a cliff edge in it's panic to be with them . If you study a shepherd & his/her dog trying to separate one or two of the sheep from the main flock you would see it is one of the most difficult manoeuvres the sheep will do everything in it's power to get back to the main flock!.