Killing Clones

I have a script where I spawn 10 enemies from a prefab.
Than on my ammo I have a script that will reduce their life totals every time they are hit. In that same script I have the destroy method if their life is less than or equal to 0. I attached the Life total to the Enemy prefab.

My Problem is this: Every time I shoot it reduces the life for all the enemies. So while the first enemie takes 3 shots to kill. Every enemy after that dies in one shot and the life total continues to go lower even in to the negatives.

Is there a script to reset the life totals or give each clone an individual life total?

sorry to say I am using Java Script for this small game

I would remove the script from the ammo and put it on the spawned prefab instead, and change it to check for a collision with a bullet object.

pseudo code:

onCollisionEnter{

  if(collision.tag = "missile"){

    myLife -= missileDamage;

  }else if (collision.tag = "laser"){

    myLife -= laserDamage;

  }
}