Issues on spawning the enemy?

Hi geeks, i have an issue on spawning the enemies. When enemies spawn in the game only one plays the animation and functionalities while the others did not play animation and functionalities. When they spawn they are not stable on the terrain and fell down on the terrain. I am attaching the script of spawning enemies, Thanks.

 public GameObject ObjectToSpawn;
 public int NumberOfEnimies;
 private float SpawnRadius=100;
 private Vector3 SpawnPosition;
 private Vector3 playerposition;

 // Use this for initialization
 void Start () {
     SpawnObject ();
 }
 
 // Update is called once per frame
 void Update () {
     
 }

 void SpawnObject()
 {
     playerposition= GameObject.FindGameObjectWithTag("Player").transform.position;
     for (int i = 0; i < NumberOfEnimies; i++) 
     {
         SpawnPosition = playerposition+ Random.insideUnitSphere * SpawnRadius;

         Instantiate (ObjectToSpawn, SpawnPosition, Quaternion.identity);

     }
 }