You can add colliders to your objects. Then, each time the mouse "enters" the collider, it calls void OnMouseEnter(). When the mouse exits, it calls void OnMouseExit(). So just create a script like:

using UnityEngine;
using System.Collections;

public class TestHover : MonoBehaviour 
{
    // Use this for initialization
    void Start () 
    {
    
    }
    
    // Update is called once per frame
    void Update () 
    {
    
    }

    void OnMouseEnter()
    {
        Debug.Log("Entering");
    }
 
    void OnMouseExit()
    {
        Debug.Log("Exiting");
    }
}

Finally, attach this script to your objects and should be ok.

You can add colliders to your objects. Then, each time the mouse "enters" the collider, it calls void OnMouseEnter(). When the mouse exits, it calls void OnMouseExit(). So just create a script like:

using UnityEngine;
using System.Collections;

public class TestHover : MonoBehaviour 
{
    // Use this for initialization
    void Start () 
    {
    
    }
    
    // Update is called once per frame
    void Update () 
    {
    
    }

    void OnMouseEnter()
    {
        Debug.Log("Entering");
    }
 
    void OnMouseExit()
    {
        Debug.Log("Exiting");
    }
}

Finally, drag and drop this script onto your objects and it should work.