How to make NPC Trigger something

Hi there,

I want to make an alarm that activates whenever a player or an NPC moves through a trigger collider. I have this working fine for the player. However, I can’t seem to get this working for the NPC. I made a new tag for NPC and assigned the NPC to it, however, it still doesn’t seem to work. I’m trying to do a similar operation on another script that opens doors, but while it works fine on the player, also doesn’t seem to trigger when the NPC enters the trigger. Any ideas?

using UnityEngine;
using System.Collections;

public class storeAlarmScript : MonoBehaviour {
	public bool enter;
	public AudioClip alarm;
	private AudioSource source;

	int count = 1;
	// Use this for initialization
	void Start () {
		enter = false;
		source = GetComponent<AudioSource> ();
	}
	
	void OnTriggerEnter (Collider other)
	{
		if (other.gameObject.tag == "Player" || other.gameObject.tag == "NPC") {
			enter = true;
			// Play the sound only on the trigger
			if(enter && count == 1)
			{
				source.PlayOneShot (alarm);
				count -= 1;
			}
		}
		Debug.Log ("Entered");
	}
	void OnTriggerExit (Collider other)
	{
		if (other.gameObject.tag == "Player" || other.gameObject.tag == "NPC") {
			enter = false;
			count = 1;
		}
		Debug.Log ("Exited");
	}
}

Does your enemy has Rigidbody?
Ok I’ll move this as Answer then (for others to find it later).
So for OnTrigger events either one (or both) of the object has to have a Rigidbody.