Instantiate creating many more instances of prefab than intended

I have a single script, StarController.cs, attached to the prefab of a star gameobject with a transform, sprite renderer, and animation. For some reason, when I call Instantiate it creates hundreds to thousands of these stars every frame, causing unity to crash. I can't seem to figure out what's wrong with this script, because I created my enemies in a similar manner with no issues.

 using UnityEngine;
 using System.Collections;
 
 public class StarController : MonoBehaviour {
 
     public GameObject _instancePrefab;
 
     const float SPAWN_RANGE = 6f;
 
     // Use this for initialization
     void Awake()
     {
         _instancePrefab = Resources.Load("Star") as GameObject;
     } 
 
     void Start()
     {
         spawnStar();
     }
 
     void Update()
     {
         GameObject[] starsToFind = GameObject.FindGameObjectsWithTag("Star");
 
         if(starsToFind.Length < 25)
         {
             spawnStar();
         }
     }
 
     void spawnStar()
     {
         Debug.Log("I'm here! Spawning stars!");
 
         Vector2 randomPos = Random.insideUnitCircle * SPAWN_RANGE;
 
         GameObject theClone = (GameObject)Instantiate(_instancePrefab, new Vector3(randomPos.x, randomPos.y, 0), transform.rotation);
 
         randomPos = new Vector2(Random.Range(.1f, .75f), 0);
 
         theClone.transform.localScale = new Vector3(randomPos.x, randomPos.x, 0f);
 
         Destroy(theClone.gameObject, 2f);
     }
     
     
 }