trying other collision with capsule collider

i have a script and a capsule collider with prefabs, i am trying to collide. when i use collisionOnEnter i dont get a callback. i only get onStart. could i use a trigger to fix this without rigidbody?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


public class ground : MonoBehaviour {
    public string wb;
    void OnCollisionEnter(Collision other){
        //if (other.gameObject.name == "") {
        wb = "alive";
        Debug.Log("I am alive!" + other.collider.name);//}
    }
     
    // Use this for initialization
    void Start () {
        wb = "other";
        Debug.Log("I am boid!");
    }

    // Update is called once per frame
    void Update () {
        if (wb == "alive"){
            //transform.SetParent ();
            wb = "sprite";
        }
        if (wb == "other") {
            transform.position += Vector3.back * Time.deltaTime*14;
        }
        if (wb == "sprite") {
            transform.rotation = Quaternion.identity;
            Debug.Log("I am sprite!");
        }
    }
}

any suggestions im using unity 5.5.0.b7

does something involved in the collision have a rigidbody attached?

no. i tried using a rigidbody as the ground but no luck. is there some other collison callback?

A rigidbody must be on the object that’s moving around. The rigidbody component is what tells the physics engine to pay attention to the object’s motion, so without it, even if you have colliders, the physics engine doesn’t even know it’s there unless a different object with a rigidbody is interacting with it.

As a rule you should set JUST colliders on the objects that you want to remain stationary (static), including triggers, but put rigidbodies AND colliders on the objects that need to be moving around and to interact with the physics engine in some way, even if the only way it’s interacting is by firing trigger events it comes into contact with. If you don’t want the physics engine to influence movement beyond the boundaries created from colliders, then use the IsKinematic setting.

thanks! use kinematic helped the problem.