public Transform player;
    public float speed = 5;
    public float seeDistance = 100;
    private NavMeshAgent nav;
    public AnimationClip idle;
    public AnimationClip walk;

    void Start()
    {
        player = GameObject.FindWithTag("Player").transform;
        nav = GetComponent<NavMeshAgent>();
        GetComponent<Animation>().AddClip(idle, "idleChicken");
        GetComponent<Animation>().AddClip(walk, "muveChicken");

    }
    void Update () {
       

        if ((Vector3.Distance(transform.position, player.transform.position) < seeDistance)
             &&(Vector3.Distance(transform.position , player.transform.position) > 1.7))
        {
            GetComponent<Animation>().CrossFade("muveChicken");
            nav.enabled = true;
            nav.SetDestination(player.position);
        }
        else
        {
            GetComponent<Animation>().CrossFade("idleChicken");
            nav.enabled = false;
        }
    }